If your Android phone is anything like mine, it's because it sucks. If I ever meet an Android programmer, I'll kick 'em in the balls.
Toys R' Us had them, and GameStop, Electronics Boutique, and other game stores like Funcoland had them. If you were in a city, you had access to Turbo systems and games. You had to keep an eye out for them, but they were there. Out in the boonies, not so much. GameStop back in the day was a good place to get games, since after a while they'd mark them down. I bought my Bonk 3 there marked down to $19!
But they didn't need to get mass market success. There's nothing wrong with a niche system, just look at the Neo-Geo. They were getting into a foreign market for the first time that they had no experience in, so the best they could hope for was being a niche player (Sony went mass market on their first try with the Playstation, but they spent billions to get there, and NEC didn't have that luxury). And they couldn't even manage that. When it comes down to it, the games make the system. And not a lot of great games made it over, just the easiest games to 'port'. Which is why there's so many shooters on the TG-16, very minimal text altering required.