[joshvm]

I think the issue is expectation. If you let people pick up loot, why can't I steal cups and pillows? The Elder Scrolls capitalised on this. Even if there's no ingame benefit to pinching a cushion, it's certainly possible.

As long as the interaction is in line with the genre, no problem. In Mario, I don't expect there to be another route to the castle so I don't look for it. In Call of Duty I don't expect to be able to loot the corpses for money.

However, if you raise expectations to the point where your audience thinks they can do anything, then they'll attempt things you never even considered. When they don't work, they get annoyed or frustrated and your game is now tarnished to them.

Minecraft is so popular in part because the world is simple enough that you can do virtually anything, within reasonable expectation.