I think there was an older interview with George Lucas that had him explaining that he drew quite a bit from the Samurai culture of Feudal/Shogunate Japan, or at least the idealized version of such. The samurai were well-equipped (both in terms of armor and weaponry) and very dangerous warriors, who adhered to a code of ethics (in theory at least) to guide their actions. For the samurai, about the only time you should draw your katana is when you intend to kill or maim the other guy, much like how in modern firearms training they teach you to only point a gun at someone if you intend to shoot them.
So while a Jedi does carry a very dangerous weapon, it's not so they can run about killing folks as they please, but rather that if push comes to shove and they have to fight, said fight will be over rather quickly.
Consider the cantina scene in A New Hope. Had Obi-Wan not quickly and literally disarmed those two goons, they would have been firing blasters into a crowded area, and quite possibly causing lots of "innocent" bystanders to be injured. While the RPG doesn't really cover the "innocent bystander" scenario, it's something that's very much a consideration whenever somebody uses a firearm in a crowded area, so that's likely to carry over to Star Wars as well. The bartender in the cantina is even screaming "No blasters, no blasters!" for just this reason as he's diving behind the counter (and into cover). Obi-Wan had already tried being reasonable with these two ("This little one's not worth the trouble. Come, let me buy you a drink...") and acted in the best means possible to resolve the situation before it escalated and caused a lot more injury. Thus, he breaks out the lightsaber, takes those two goons down in a matter of seconds, and nobody else got hurt beyond the two individuals that escalated the argument into violence.
It's obvious from the Prequel films that Jedi aren't shy about violence, but it's not their go-to solution if they can help it. Qui-Gon Jinn in TPM could have easily killed Watto and stolen the parts needed to fix the Queen's ship... but he didn't. He offered to pay for them, tried a mind trick to get Watto to accept the money he was offering, and when that didn't work set off (in a bit of a huff) to try and find some other non-violent solution. Your typical party of wandering murder-hobos would probably have just killed Watto, ransacked his shop, and gone about their merry blood-spattered way.
Also from TPM, you have Qui-Gon and Obi-Wan very calmly sitting and waiting to meet with the Trade Federation leaders, and only break out the lightsabers when the Viceroy makes the first move and blows up the non-armed ship they arrived in. Even then, they don't go charging into battle until after the room is being pumped full of deadly gas, at which point it becomes clear that the Trade Federation leadership isn't interested in a peaceful resolution.
In AotC, yes Obi-Wan did literally disarm Zam, but she'd proven herself to be dangerous already and had a blaster drawn and ready to shoot Obi-Wan in the back. As soon as her arm was lopped off, the lightsaber was put away and Obi-Wan and Anakin hauled out of the nightclub to question her.
In RotJ, we've got Luke almost bending over backwards to give Jabba a chance to peacefully resolve the issue of Han Solo's imprisonment, While Luke may have known such efforts were doomed from the start, he at least tried, though he probably took a little too much joy in setting things up to bring Jabba's criminal endeavors to a violent end, but at the same time Luke wasn't really a Jedi Knight just yet (had the skills, just not the proper mindset), and in fact part of the film's story is that he's teetering on the edge of becoming just like his father.