... Finally, as should be relatively obvious, if there are 1,000 elements that can be used to throw together a campaign, different groups of those elements can create novelty that will last far longer than any human lifetime.
OTOH, if every campaign must use all those elements, you have only a single set. Eventually, everything seems to look a lot like everything else.
Me, I'd rather game in a world with some form of cohesive vision, from either side of the screen. I've never seen a kitchen sink (even with a good GM) that came close to the cohesive vision a more judicious pruning can create (even with an average GM). YMMV.
Yeah, with the caveat that the purpose and fun of a kitchen sink setting is not found in a cohesive vision. The whole point of it is that it just goes all over the place.
I've
always seen the primary purpose of having a giant monster manual as: "Here is a list of things from which I can pick a subset to make an interesting campaign." As games have added options for different kinds of magic, races, etc., I've felt the same way. Sure, every now and then you can just use the whole thing, but that is really just the "subset that happens to include everything."
People who study creativity sometimes do this little exercise with children. They'll get two groups of, say, six year olds. One group is given a box of crayons and some paper and asked to draw something. The other group is given a box of crayons and some paper and is asked to pick from a short list of things to draw.
Now the interesting thing is that at least a few people in both groups will be very frustrated, either by the wide-open or restricted nature of their respective groups. And even more interesting, in the first group you may get someone that feel restricted being limited to crayons and paper, while in the second, you may very well get someone that wants you to pick something from the list, for them. But the most interesting part, at least to me, is that once you get all of the "deciding what to do" part settled for everyone, the amount of "creativity" demonstrated will be more or less the same.
Generally speaking, people who want some guidance, aka "limits are freeing", outnumber the other side, aka "wide open", by a substantial amount. Differences in the amount of limits found useful obscure this fact in everyday life.
Where people naturally fall on this range varies quite a bit. However, as we get older, we start compensating. Note that we compensate; we don't change our essential natures. Most people who want you to pick for them learn how to pick for themselves. But they will probably never be really "creative" in their picks. They will be creative once they make the picks. Most people who want everything wide open will learn to accept some practical limits and then get on with producing something. (Possibly using their grudging acceptance as a spur: See Michelangelo the frustrated sculpter with a commission to paint a certain ceiling.) There are, however, exceptions--whether from experience, training, temper, or real extremes in creative thinking--no one really knows yet.
If you've made it this far, there is a relevant point. I'm pretty much in the "limits are freeing" camp. I
need some hard limits to be easily creative, whether imposed by others or myself. Moreover,
everyone in our group is the same way. We can do wide open, but wide open necessarily means a certain amount of floundering around while we impose the limits on ourselves, so that we can get on with the fun parts.
Heck, our pre-campaign discussions are essentially about throwing things out. Either we throw something out directly (e.g. this 3E campaign has no goblins, kobolds, or orcs; all the low-level humanoid threats are PC races or gnolls) or implicity (e.g. this campaign is about humans and dwarves; other races will be niche, no more than one per player, and rarely encountered). This goes round and round, with people throwing out, discussing, and accepting/rejecting ideas, until we have enough to work up a pre-campaign document. Sometimes, the players are more vague--just do one of your niche campaigns--which means that I'll limit myself to about 20 monsters as recurring foes, and maybe another 20-40 as rarely appearing.
Say you are from the other side of the creativity spectrum. You are going to be a little frustrated with our campaigns. If you came in mid-campaign, you'd probably be pulling your hair out. Because not only am I not going to allow you to play your kitchen sink idea, the reason is likely inexplicable to you. Even if you participate in the pre-campaign discussion, you'll be frustrated. Because for some reason, it is difficult for many of the "wide open" creativity folks to really grasp that other people aren't like them--much like night owls sort of understand morning people, if only from having to get up and go to school or work, but morning people seldom really understand night owls. Just get up on a regular basis, and you'll like it and be cheerful like me! Sounds a lot like "trying broccoli," doesn't it?
Strangely enough, I ran a few games in college where we accommodated this divide somewhat. We had one radically "wide open" person in a group of otherwise "limits are freeing" group. It was actually a house rule in our campaigns that the "wide open" guy got to break any limit he chose. This was a bit of group judo--it kept the limits there and useful for everyone else, but also gave him something to react against. It worked well enough for college, but it was very draining for the three of us who GM'd. I'm too old to do that anymore. (Also, it worked because we were all friends, and the "wide open" guy was one of the nicest people you would ever meet. He knew we were making an exception to enhance his fun, and he was very careful not to use it to dick with the game. If a GM blanched at one of his character ideas--well, he had 20 others that he would consider.)
I suspect that some of the talking past each other in this topic, and some of the, well, knee jerk reactions from both sides, is coming from different sides of this same issue. I know for me, a person saying, "the player can do anything they want with their character, and the GM should find a way to accommodate them," is setting off all kinds of buttons. "Accommodate" his character is sometimes not "reskin a couple of flavor ideas in town X and just roll with it." Accommodate his character is sometimes "rip out the heart and soul of what drives the creativity for the GM and every other player in this campaign." And from the outside, it will be really hard to tell where on the spectrum a given request falls.
And it is hard to explain. This long post is barely scratching the surface. That's why the last new player I had in the game got essentially this explanation: "We like restrictions. Some of them may not make sense at first, and we won't always give clear reasons. But there are good reasons. Stick around for awhile, and it will become clear to you." It's a lot easier to explain once a person has experienced it for awhile.