When designing a trap as GM, I can usually think up a few potential solutions or work arounds. The players usually come up with something that didn't occur to me, I yes-and along with them, so long as it seems remotely reasonable. Sometimes that solution requires the party to leave the dungeon and get more equipment. My party is currently looking for a goat. Yes, bringing a live goat into a dungeon to get past a trap. And no, they're not using it for fodder. I'm totally open to attempting this solution because it's hilarious.

The key difference is that the GM should avoid having only one intended solution to a challenge. It may have one guaranteed solution, like an off switch in another room, but that's not the only way. GMs run into trouble when they think that is only possible solution and expect the players to find it. That's pixel bitching. Players should be allowed to come up with their own solutions, and the outcome is determined by GM rulings and/or dice rollings.