I think what folks see as "dated" is just stuff that is not old enough to be vintage, yet we are just sick of looking at it. I personally don't LOVE eighties fabrics, but maybe that is because that was when I began my foray into quilting and I made a lot of newbie mistakes...so hence the fabric reminds me of that.
The trend in quilting seems to be "Modern" more and more. Maybe that is why older fabrics are less popular. They don't work as well in modern designs.