Yes on both counts, I would wager it is a regional thing, I know that one of the best f/w plant suppliers is growing them out in Ramona, I'm sure there are others. I am of the opinion, though, that if they see it, they will come. Set up a few GORGEOUS planted tanks, maintain them well (fish like discus and rainbows tend to show them off best, I think) and customers WILL want them. We sold MANY water conditioners, craploads of peat, and many RO/DI units because our water is so hard out here.
We sold several brands of additives, I liked SeaChem best, though. There were several customers who had to have EVERYTHING Dupla they could get their hands on. We also (I think the new owners still sell it) FAMA mag, which many shops won't because of the online/mail order competition. Dougie felt it was better to give people the choice, and he usually got the business (supported his family for over 40 years in this bidness) because he employed people who specialized in different areas. Even though I was the "reef chick", I was responsible for all display tanks in the shop, and by far my favorite was my planted tank.