I think it depends on your experiences. I was 9 when T2 was new, I caught the marketing, I had the toys, and because of timing, it aired on TV and was edited so my parents would let me watch it, I had parents that wouldn't let a kid that young watch and R movie, and I don't hold it against them. Terminator 2 and Rambo 3 were my big breaks into more adult movies and action films, I grew up playing with T2 toys and imitating the Arnie shotgun load with toy rifles I had and I would sneak peaks of TV shows doing stories on T2. I was engrossed in T2 long before I had a chance to see T1, again because of it needed to be on TV and edited.
I think favoritism of one over the other comes down to the order you viewed them in, if you were part of the 80s when T1 came out or more a 90s kid when T2 was the big thing. You can also just prefer one over the other anyway too.
Another thing for me is that I enjoy Schwarzenegger as the hero. I'm sure for people who saw T1 back in the day, Arnie wasn't such a household name that him as the villain was more acceptable, for me, with Kidergarten Cop and Twins and movies like that, I grew up liking him as a hero like Stallone. I enjoy T1, but I prefer Arnie as the core hero like T2. Also, for my age, T2's world is just more appealing, I was to young in the 80s to ever like the styles or pick them up, so a lot of things in T1 are bizarre to me. Many people love the Tech Noir look for the T-800, I really don't care for the goofy outfit at all, it doesn't even seem plausible that any person would wear that. I like the biker look because it seems much more normal and it's a lot like T2.
