From my experience, RPG style games tend to be played by a younger crowd, the reason why seems to be the excessive use of fantasy elements in it, tied usually to an artistic design that honestly always looks aimed at kids.
Plus RPG's tend to be slow games with long stories, people who work and have a family don't have time for slow progressing satisfaction, instead this people look for quick satisfaction games.
Tactical RPG's suffer even more from this because they might be perceived as too slow and often requires a lot more of thinking, than just spamming the best powers your party has in a regular RPG.