i think one thing about jl users is a lot of kids with jl just have their parents go buy them some subs, if they are lucky they throw some infinity or sony xplod or alpine door speakers in, half of the equipment isn't half bad, but i think that a lot of the kids just get the stuff and aren't intelligent about installs, and so they make JL look bad. but I think a lot of JL and other big name brands have very good equipment, its just mainstream stuff isn't seen as often installed correctly as say, the RE, adire, eD, SS, or other equipment that mainly CA hobbyists use, people who spend their time reading and working with CA
I see your point, but any equipment can be used in a poor install(ED, JL, Alpine, etc). I have seen MANY "newbies" have the lesser known stuff recommended and then be told "oh just install it yourself" only to find their subs and or amps fried due to lack of installation knowledge(or using the wrong box for the sub, etc).
One could argue that the mainstream stuff might more often be properly installed(if, as you say, mommy and daddy are paying for it, they might certainly be paying for installs as well). Sure there are people who have zero clue and have never used JL who will scream that JL is the best. There are also people(I have seen many of them on the forums) who will say JL sucks without having never used it(or they will preach how great ED/Adire/whoever is without using that equipment). I have seen ED hyped so much that one model of their subs was being recommended months before the sub was actually released to the public. Internet hype is crazy(not saying ED or any other brand makes crappy stuff, just saying, in many cases, the hype is not yet justified).
I would not necessarily say that car audio enthusiasts are more likely to use less known brands either. Some do, some don't. Like I mentioned earlier, I use what sounds good to my ears(I also am great friends with the owners of the local shop, and I get very nice discounts on equipment that they sell). I don't like taking chances on equipment. If I can't hear it/touch it first, I am not very likely to just order speakers/subs online.
Parents can buy the RE/ED/Adire stuff too. I think, to many on the forums, the perception is that is just isn't cool to use "mainstream" products. Some have the attitude that "if you know what you are doing then you wouldn't use JL/RF/whatever other "mainstream brand." Like I said, JL's reputation is there for a reason. JL has been incredibly reliable for the local shop(by "incredibly reliable," I mean last I knew, they had 2 12W3s come back blown EVER). Those are the ONLY jl subs that have come back to them, blown(and they have sold a ton of JL subs in the past 4 years). It is easy to see why dealers want to sell the stuff. The local shop just sells it, it sounds good, and it doesn't come back. It is also easy for them to get. There are no 6 month back orders/delays on the subs.
What I find funny is many of the people who will look down upon those who use JL will also run such "mainstream" brands as Alpine or Pioneer. That is just an observation from being on several forums for the past 3-4 years.
Some may think JL's retail pricing is too high, but also, I have seen many cases where people are getting great deals on w7s, w3v2s, w6v2s, etc through authorized dealers.
JL is worth looking it. If somebody thinks they get the same(or nearly the same) performance from another brand, buy it, but looking down on people who run JL is idiotic(that is not directed at anyone inparticular...just a general comment).