If you go to the same gym you are already in-grouped. It is the insecurity of the new person who would think they are out-grouped.
Meatheads love new lifters. No one showed up at their first gym 230lbs and ripped. Even the biggest guy in the gym can relate to being the intimidated new lifter.
The only difference I would think between a gym with weights and a climbing gym is that the people at the climbing gym look less intimidating.
Also - weight training is also a highly technical problem-oriented discipline. You can do it for years and still not have things working the right way. The techniques are evolving as well. So - lots of problem solving and discovery.
FYI - one of my favorite sites of all time and certainly the technical view on things: exrx.net
The people who talk shit about those people are generally insecure themselves and projecting their inner monologues on them - and the thing is, all the experienced people have been there and done that. Breaking through that is hard, but so rewarding.
You know, people say this a lot about "typical" weight lifting focused gyms, but I've found nothing but the opposite. There are certainly some people who are in there that are judgy (the are everywhere) but the vast majority are either there to do their workouts and leave, or are very friendly. And I've done most of my training in gyms in Manhattan and Paris, two places not known for friendly people.