Yeah, TG16 stuff is all but non-existent in the wild, but I disagree with the lack of quality HuCards. Even just domestically, there are lots of great HuCards... Neutopia I & II, Ninja Spirit, the Bonk games, Air Zonk, the Star Soldiers, Sinistron, Blazing Lazers, the Legendary Axes, Dungeon Explorer, and many more. I honestly really feel it stands up really well over all. Yeah, Yo Bro is no Zombies Ate My Neighbors, and Timeball and Drop Off suck really hard, but it skews to average or better for the majority in my book. Cadash, Final Lap Twin, SideArms...
Definitely don't blame people for emulating, though. Prices on that stuff are out of control. Ever since completionists started going after small library systems like Virtual Boy or 32x that were inexpensive forever and then popped off a few years ago when collecting blew up. Neo Geo games costing more than cars, Waterworld hitting triple digits at times, Magical Chase going from about $70 for almost 20 years before jumping into the thousands... It's all crazy. Turbo seems to be one of those that the folks that got their Jaguar CD and Virtual Boy collections finished all jumped on at the same time.
That might be my favorite thing about the Genesis. Yeah, it has its collectors and fanboys, but most of its awesome stuff is so accessible and still cheap even at retail. I can go out any given day and find something at least decent for five bucks or less, so that's neat to me.