I did two extract + specialty-grain batches. Both came out pretty well (Though the second, quite sadly, went bad after a few months in bottles. The truly unfortunate thing was that I discovered this when the scoresheets came back with dismal numbers and comments about its being astringent, unpleasant, and, "hard to drink," which was completely at odds with my opinion... opened the last bottle that was lying around and, well, there was a bug of some sort in there!)
I've been doing partial mashes since then, mostly because I can. The beers have been as good or better, though I think that's as much a function of some experience and recipe choices as anything. I am just doing BIAB partial mashing, so the additional equipment is just a mesh bag, and it takes an extra couple hours on brew day. To me, though, I enjoy the additional process steps. I'm not just brewing beer for the beer itself, I like to take part in as much of the process as I can. Someday I'll probably go to all-grain, but the space and equipment for that step are not going to fit in my lifestyle right now.
Projecting my own thoughts on the world at large, I think this is probably a common reason. Many people like to DIY all the way, and all-grain is "more DIY" than extract brewing. Note that there is a lot further you can take it---developing and propagating yeast strains, etc---but all-grain is a definite plateau in terms of cost and complexity. Taking over much more of the process at home requires a much larger investment in equipment, time, and expertise, so it's a natural spot for a lot of people to settle.
I don't know that I see people who look down on extract brewers very often, though perhaps people are sometimes quick to encourage others to go to all-grain. That's a bit unfair, as not everyone does or needs to aspire to go to all grain, but at the same time I don't see this as being a serious problem. If you don't want to, just ignore that suggestion. It's been mentioned above that "support" in terms of kits is plentiful for extract brewers. It's perhaps true that recipes are harder to come by on here for extract brewers, but that's probably because the people who are involved enough to be developing their own recipes are more likely to be working with an all-grain process. However, it's not difficult to convert an all-grain recipe to extract or partial mash, so even this isn't a huge hurdle.