If you take them out to feed they'll think there's a possibility they'll be fed? LOL. I actually hope you were just kidding. Feeding in the enclosure is simply about saving time and it's much easier then having to relocate, also you're not handling a snake after it's eaten so no risk of regurgitating. There is no difference between feeding in the tank or moving to feed elsewhere, it's simply a matter of preference.
I just wanted to point out actual facts instead of assumptions that you posted.