I'm still relatively new to all this but from my experience so far, to successfully be lightweight requires a lot of knowledge and that knowledge does not come from a quick convo with a retail associate at REI or reading a book and calling it good. It comes with time, effort, study, and quite a bit of experimentation to find the right system that works for you. Sure there are lighter "traditional" products out there for those with the cash and you can tell someone to leave some luxuries behind and squeeze out excess toothpaste, etc. These only get you so far, though, and everything else requires a measurable degree of knowledge and confidence before you can actually go out and do it safely.
Like I'm sure many people on this site have, I started out heavy not knowing any better. I took some stuff I already had, bought a bunch of fancy gear that I didn't have and thought I needed (mostly on advice from sales people at the gear shop), bought way too much heavy foods, and loaded it all up together and me and a buddy headed out to do four pass loop in the Rockies. That is quite an aggressive hike for a first timer and my 55+ lb pack didn't help much (funny thing is that I was told to cut the handle off my toothbrush so I did...lol). That was 2 years ago. The next time I went backpacking was a year later and I took me and my girlfriend (also a first timer) to the same area but a much easier trail. Using lessons learned from the previous year, I was able to leave behind some extra clothes, cut down on luxuries, switch to mountain house meals, and build packs for the both of us that weighed 40-45lbs each with food and water (didn't bother with cutting the toothbrush this time though). Quite an improvement but still felt too heavy for my tastes (and hers). I really enjoy backpacking in the mountains, and want to do it more often than once a year, but if I was to continue doing this, I had to find a better way. I went online and found sites like BPL.com since there really isn't any kind of local source that taught lightweight packing in my neighborhood. Since then it's taken me months of research, experimentation and study to get me just to the 18lb base weight (with bear cannister) on my 3rd major trip that I took this past month. I went to Glacier National Park for 6 days and my total pack weight was 28lbs with food/fuel/water at the trailhead.
I know this is only just on the border of actually being considered lightweight but to me it was quite an accomplishment. Even with all the knowledge I've gained and things I've tried, I still consider myself a rookie because there's so much more to learn and experiment with. I've bought and sold quite a few pieces of equipment and spent a lot of money on trial and error, experimentation and agonized over whether this or that was the best decision or not... I'm sure a lot of you have done similar things to get to where you are now. Am I done? Heck no, my goal is to get lighter and lighter until I've found my ideal system that works for me but the point is that's it's not going to happen overnight. If it were an easy matter of just copying someone's UL gearlist, buying the stuff and just hitting the trail with it, I would have done so and saved myself a lot of time, money and headaches. I would have also lost out on the fun and had less appreciation for what I've accomplished.
Like someone posted previously, most backpackers we see out there are casual types that get out maybe once or twice a year (if even that) and usually want to do big trips. They don't have the time or inclination to figure out all this stuff. They want to be able to get out there as easy and efficient as possible, have a good time and then get back to life. They don't care to spend time at home looking at spreadsheets and weighing out each of their items or even doing a bunch of short outings to try out new techniques. Modern advancements in technology have allowed more and more people to get out there but what that does is just produce more and more traditional style and fly-by-night backpackers. You don't need a lot of knowledge to survive in the backcountry these days if you have enough modern (heavy but easy to use) equipment. Load a person up, give him a big heavy survival kit to boost confidence and send them on their way.
To sum up this long winded and direction-less post, I think lightweight backpacking is and will likely always be a niche in the big wide world of backpacking. As more and more people are introduced into backpacking, I'm sure that the lightweight community will continue to grow as some people convert over, but it will still be on the small side of the overall ratio of traditional to lightweight packers.
I personally like that it's still a relatively small community that I can claim to be a part of. As bad as this sounds, I for one cannot wait for the day that I get to fly past a bunch of packers huffing and wheezing their way up a pass as they ask me about how my "day hike" is going.