Well, you know why they don't do it, of course. Having a second analog stick means more work on them and it means they'll have to actually expand their knowledge of game development. Since this is Game Freak we're talking about, well.
As for remakes... I'm not sure they'll keep on doing them, but then again, with the influx of generation 4 kids on the internet, I guess even those have become beloved classics (ewww) that could warrant a remake. If they do keep coming, then I'm happy Unova and Kalos remakes will look even better than this, those games were awesome (then again OR/AS was garbage so I'm concerned about them screwing up more of these).
Yeah... ORAS doesn't make me confident for a Sinnoh remake, but I've given up on expecting anything special from GF. In many ways, I hope Sinnoh skips this gen with Let's Go serving as the remakes. On the other hand, ORAS tells me that perhaps a Platinum remake should be left in my imagination.
I get that you don't like the Sinnoh games, but they feel like the last games with a geographically complex region traversal wise. It would really bum me out if we didn't get at least one of those regions done to scale. The Unova games are, to me, the last competent Pokemon games, but they started the rapid streamlining of exploration we have now. S/S look like the same thing, so I feel like after the Sinnoh remakes, we'll literally never get a Pokemon game designed the way I like them again. Short of a BotW-style reboot. Which I don't ever see happening, frankly.
Well, this is new.