Gotcha, yes I have a lot of "nerd" friends as well (I generally consider myself one). We haven't talked much about the movie since it came out. In general, most of the ones I talked to didn't like it. My 10-year-old (at the time) son liked it, but he hasn't asked to even see it again, and we didn't really talk about it after leaving the theater.
I'm good with having a civil conversation about it. I respect the opinions of those who say they liked it. Everybody's different.
Luke was always the guy who dashed in to save his friends. Even in RotJ, he basically gave up his life to save his Dad. I don't think even old man Luke would cause the problem he did and then hide away like Obi and Yoda. Of course, they didn't cause the problem, they just didn't prevent it.
But let's say old man Luke does get to that point. I don't feel like the movie got me there in a natural way. They didn't spend enough story developing that angle. I never felt like, "oh, that makes sense for Luke's character." Or, "well, Luke was never that way before, but the movie did a good job of showing me why he's that way now." Just didn't feel it, and I'm pretty sure Mark Hamill didn't either.
The movie had a lot more problems, but this is the one that I just couldn't get past. Other things include, opening that can of worms that is light speed ballistics. The casino side bar that seemingly did nothing. The weird, slow "bombers" and other strange acts of physics (almost always a problem in scifi, but this one seemed to relish it a bit). Not sacrificing yourself to save your friends but also sacrificing yourself to save your friends. The old trope of "I'm not going to tell you my plan, which is of course going to cause huge problems for us." The ending where they seem kind of happy, but there's like 12 people left on the Falcon, and every ally they had in the galaxy has either ignored them or died. Most of these I can even swim past, but they just kept adding up.
The movie did have some great visuals and some cool moments.