system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars: ESB] Why didn't Luke just switch on his lightsaber to free it from the ice?

He's hanging there upside down in the Wampa cave and struggling to pull it from where it's frozen in place. If he just switched the damn thing on it would melt the ice right away and no longer be trapped. 

I can think of two possible explanations:

1) He didn't have the finesse to operate the switch with the force at that point in his training.

2) He didn't want to pull the lightsaber towards himself while it was on in case he accidentally decapitated himself or something. However, once he does get a hold of it, he has no trouble sweeping it at his feet to free himself while neatly avoiding injury.

What do you think?
gpt
Luke turns on the lightsaber, it instantly vaporizes the ice around the blade...where does that instantly created vapor go with a lightsaber blade plugging the only escape route?

It shoots out the lightsaber at explosive speed, and Luke has just created an unpredictable plasma bladed projectile, weighted on one end so it spins and gyrates as well, moving so fast he can barely predict it's movements, in a limited space where he is unable to move.

I don't think a wise Jedi would want to unleash a lightsaber buzzsaw inside a chamber he's trapped in.

Also? Even if he doesn't cleave himself into pieces by this action, wherever the lightsaber lands, it's likely not going to be closer than it was, so now he's got to summon up even more reserves to get it into his hand. It looks like he was barely able to summon up the energy or the concentration to make that first attempt.

Your explanations work too, but you should check out how powerful expanding water becomes when you do a rapid phase change from even liquid to vapor. Ice to vapor would be even more violent.

Not something you try in an enclosed space and without being able to dodge or take cover.