Good points!
I think the art field may also be growing in an "accidental" way as a result of technology. At our gallery, we see more and more people who tell us they are doing "creative things" because they MISS actually "using their hands" to create. These days, all we seem to do is type on a keyboard or use a touchpad... people are starting to miss actually using their hands-- rather than technology-- to create. And so, some of the "art therapy" (and other things) you mention are becoming more and more popular.