It seems to me that much of the increasing popularity of quilting has something to do with the relative ease that we have of getting these projects done. In my case, I do them on a sewing and embroidery machine because, although I admire hand work, I don't have the patience or desire to do that. It's a hobby and so I focus on what I find enjoyable, which is both the piecing and the quilting. I could probably get a nice longarm set up and do have the room for it, if I got rid of some stuff we don't use, such as a treadmill. I've watched how that process is done and so far it hasn't attracted me enough to justify the expense. I could buy a lot of fabric for what those things cost. Quilting my own is a bit of a challenge as I do it now, but I don't want other people to finish my projects. I like to see them through to completion on my own, even in the case of the ones that fall by the wayside for months or years - the UFO pile! Eventually, I rediscover them and get inspired to finish them, and it's always rewarding to have accomplished something.
Ultimately, it's fine whatever means people want to use to get their quilts done, because these days we create quilts because it's what we want to do. The fact that many people who are participating in this hobby can justify the cost of either buying a longarm setup or sending their quilts out just illustrates that the hobby has caught on increasingly among people who have more money than time. That shouldn't be too surprising in a society where most adults have full time jobs.