Hi Adyson,
Another potential is that for many of us more mature folks, we grew up in a time where this was not tolerated on any level and could in some cases get you jailed/institutionalized or at the very least beat up. So we retreated to repression and closets to imbibe in making ourselves happy. This predates the internet in most cases so we felt alone. Once the internet came along and we found a community of sorts we jumped in with both feet because we found kindred spirits we could talk to and identify with. Even though we live in a more tolerant society today you also have to remember our contemporaries may not be as tolerant as your contemporaries so it is easier to come here and discuss then with you buddies over beer. For the younger crowd, being TG is more known and for some you have been exposed to it, may have other friends like you or, your group of friends are quite cool with it. As such, your generation (and not all) have an easier time assimilating into society and actually living your life openly if you choose . . . Yup not that simple for all in your generation but it might explain why more older folks are here.
Cheers
Isha