I'm telling you that the world works in ways that make sense to me. No doubt some of that comes to my tastes--I don't like steampunk/magicpunk much, and don't want mecha in my D&D game, thanks much, and Warforged in D&D are ... more than little OP, IMO.In short you're telling me that every wizard who tries their hand at something approaching robotics is stupid and careless. And that magic only works in very specific ways and ways that shut down player ideas. And they work in those ways because you, the DM, who has absolute control, has decided they do that.
This all tells me that what you're looking for is excuses to say no. Me, when I DM I'm looking for excuses to say yes - and even more than that excuses to say "Yeeeesssssss..." with an evil grin.
I don't have absolute control of the world, once PCs start moving around in it; that was a lesson I was really slow to learn, but I learned it. What I'm looking for is to have fun, too, and there are some things I dislike strongly enough that DMing them doesn't sound like fun to me. This is why I only have 35 choices for PC races on the "default yes" list and ask players to talk with me about anything else.
I DM way more than I play, too; I'm probably going to walk away from the one steady 5E campaign I'm playing in, because the DM isn't running the kind of game I want (I've had my fill and more of choose-the-lesser-evil scenarios). I'm fortunate that I have some good friends to play with me, and that I was able to find some other good players running at game stores. I haven't wanted to say no much to the players at my tables.As I have pointed out I DM more than I play and even when I'm a player there are more other players at the table than there are DMs. I have also in my time only ever once run into a player where the problem was player entitlement*. I can think of a number of bad DMs I've played with
where the problem was DM entitlement and the DM deciding that they should control as much as possible on both sides of the screen to the detriment of the fun of the players.
* This is not the only potential problem of course.