I started quilting in 1989. Quilting was fairly popular even then - there were quilt shops around and guilds were available to join. Of course, the profusion of fabric was certainly not like it is today! I think it wasn't the explosion of quilting, but the internet that made it feel like an explosion. Quilting is definitely more popular and the market for it is bigger today, but the internet helped it become the huge force it is today. When I started, there was no internet and there was no way to share or learn beyond your own community for the most part.
Today we have wonderful things like the QB where we share from around the world and we can have quilting conversations at our fingertips any time we want. We can view the fabrics out and coming from manufacturers, and find them online if we don't see them in our LQS. Seeing patterns, and machines, and long-arms create a market where little would have existed in the past. So I think it's the exposure that's really pushed the growth of quilting. Of course, that's just my opinion.