The episode that resulted in this thread in the first place was a true case of getting stuck. It involved exploiting a bug - an error in the way the level was designed - to get into a situation that the player was never intended to. Compounding this is the availability of a pattern buffer, making it possible to save an unplayable saved game. Once the player saves their game in such a situation, the only way to continue is to either go back to an earlier saved game if they have one, start the entire scenario over from the first level or to cheat. Examples of these can be found in M Evil and Trojan, to name a few. I'm not aware of any such trap in any game in the original trilogy.
Infinite loops are completely different. This involves the player accidentally or intentionally going back to an earlier level and continuing to do so. These opportunities to loop are generally intential, rather than mistakes. It's understandable for the player to make this mistake once, but to continue to make the same mistake over and over again is, well, pretty stupid. If at first you don't succeed, try to figure out what you did wrong in the first place.
There is a 3rd category of getting trapped - the so-called suicide trap in which the player finds themself it a pit or other sort of place from which they can't escape. The only way to escape is to either quit the game or, literally, committ suicide. Since the player can't save their game, there is no significant harm done. There are examples of both deliberate suicide traps and mistakes as well.
