I had a player that was one of those players that would try to do things way outside the rules all of the time. So I would tell them no, the game doesn't work that way and ask what they were trying to do. Based on what they were attempting I'd see if there was some way we could get close to what they were attempting but sometimes the answer was no. Want to swing from a chandelier even though there's no rules for it? No problem, give me a check. Try to do something completely outside of the capability of the character? I'm not going to be an "always say yes" kind of DM.
Limitations on what PCs, and trying to solve situations within those limitations, is part of the fun of the game.
Sure, but I think here is a bit different.
Here It's not saying to the player "What you're trying to do isn't RAW or even close..."
it's "I know what your trying to do IS RAW but I'm going to disallow it because..."
The latter is likely to happen MUCH less often. If it's happening a lot there is likely some kind of major disconnect between the player and DM - and that needs to be ironed out.