He is intended to be the simplest class/subclass to play, with almost no moving parts. Yet he is intended to be effective enough to not make a player who rolls one to regret his choice. Now there are some goals here which are inherently self-contradictory.
I disagree that it is inherently self-contradictory; it could be true in this case, but isn't always. I believe simple can be just as effective, or more effective, especially over long periods of time. I think this because simple can be more reliable.
No offense intended. I was under the impression that the idea that plumbing was somehow related RPing ability was an idea that has been sufficiently trashed that no one would actually imagine I meant it literally.
Do you know a better shorthand for "the simple class for that guy who like to play but never really read the rules and hasn't figured out AoO even though he's been playing a polearm fighter for 3 edition"?
And here again, your point of view is that if someone prefers a simple class, it must be that they are simpletons. Sure, that polearm guy does exist, but you're generalizing a bit much, and putting yet another label on champion players; you're saying they are incompetent. I don't think you believe that's true in all cases but you seem to think that's true in the majority, and I disagree, but of course, my experiences may just differ.
Those players of mine that don't want to play a spellcasting ranger or a battlemaster fighter are the same ones that disliked 4e (until Essentials). They are some of the smartest people I know. They play D&D to relax and get away from their challenging, technical jobs. They are typically more introverted, and don't have the mental energy when socializing to also optimize a character with load of options. They don't play poorly, they just want something simple to have fun with and be helpful to the party.
Getting back to the point of your thread, which isn't a bad one, is the Champion a good enough option? I think "will they regret taking this class?" is a valid question, because like I said, they do very much want to be helpful to the group, but I believe there is more to it than DPR or how it competes with the other fighter subclasses, I believe some of the appeal has to do with reliability.
In my experience, the player that prefers a simple character may be fine with simply attacking every turn, as long as they are doing their part, even if they lag behind a bit in damage, because they are doing reliable damage. They take pride in being the rock that the party builds around, and seem to enjoy watching everyone else casting spells, setting up sneak attacks, etc. I'm comparing it in my mind to 2e and earlier fighters, as I haven't run much 5e yet. I suspect time at the table with the class will be the only thing that answers that, rather than theory crafting on paper. With bounded accuracy, characters hit a lot more, so I see the Champion as being fairly reliable, which is what such players tend to go for, and I think it's a fine option, but that's just my guess and I'm thinking it will take time to tell, as spells and other abilities offer a lot of flexibility and that can be powerful.