Buying things in bars is a long and noble tradition for makeshift heroes. It doesn't necessarily have to be weapons. Just make sure you visit bars and buy something.
"They come in pints?"
Commentary by memnarch (who has not seen the movie)
As always, this is all really Qui-Gon's fault when you get down to it. Though to be fair, there wouldn't have been much of a campaign if Jim hadn't parried those blaster shots leading to how much of a defensive weapon laser swords are. But then that wouldn't have been needed if negotiations had happened so.... But that's just the way of good tabletop campaigns isn't it? Player choices having a lasting impact on the world around them? Sure, there could be bigger events going on elsewhere and possibly not even related to the players, but the players are where the story happens and if the player choices do have a huge impact, so much the better.
And I'd partially agree with Luke here. Part of warfare is defense. Attack attack attack only works up until the other side successfully blocks or deflects and then counter attacks back. If there's no defense at all, then there's a huge risk of losing when there's any slip up or mistake. Admittedly, Jedi aren't going to be much good at deflecting ship-sized laser blasts, but even just being able to fly and survive for a long period of time in a fight would be a very helpful skill. Which, barring a large target of opportunity like a Death Star to fly against and destroy, would be best served on defense.
Hm. Maybe this dialogue is actually close to the movie here? Being able to out-fly and defend against a chasing fleet would be incredibly helpful, and we've already seen the chasing fleet twice so far. There's a lot of guess work here, and it might be a little too complex a concept for a Disney movie, but that could fit the plot as shown at least.
Luke: These tomes chronicle the rise of the Jedi. But there was also a fall.
Rey: How so?
Luke: 66 years ago, as a young padawan, my master Obi-Wan Kenobi was sent to Naboo with his master, Qui-Gon Jinn.
Luke: They were there to negotiate, not fight a war. But a few years later that’s exactly what the Jedi were doing, fighting in the Droid Wars.
Luke: The philosophy of the Jedi became corrupted, influenced by my father, your grandfather, Anakin.
Luke: Jedi are guardians of peace. That’s why we use cheap laser swords that anyone can buy in a bar. Because they’re so underpowered and defensive compared to a blaster.
Luke: You can only protect the Resistance. You cannot fight a war for them.
Rey: I dunno. I bet I could if I had better weapons.