Ah, see, I have a response to that. And it's exactly the kind of response you can expect from me.
While there should be no good reason why they can't make a mighty TMNT game of that caliber (case in point, I don't think anyone ever expected Batman: Arkham Asylum to turn out to be one of the single best games of the entire X-Box 360/PS3 generation - Rocksteady was a complete unknown at the time) There actually IS a reason why they're doing this.
One I've already mentioned, and that's Streets of Rage 4. So I'll skip that part.
Another is that the publisher is Nick Games, after the rights reverted from Konami to Ubisoft to Activision to now. Since Nick owns the rights to TMNT, but NOT the full rights to any of the earlier games, this is something they actually can do (they did use a piece of music from the old 90's video games in a motion comic promoting the 2012 cartoon, but who knows besides). Nick is not a company that focuses on video games (they mostly put out mobile and browser games, from what I've seen) so I don't know if they care to make something more ambitious and risky.
Lastly, they have tried to make TMNT games more substantially elaborate than this in the past, and failed badly. Out of the Shadows (no relation to the film) was a poor 3D action game with a clunky imitation of Arkham-style combat that was based on the 2012 cartoon but drastically changed the art style and voice actors (and for some reason had Karai wearing a mask). It was so poorly received the PS3 version was yanked from the storefront so they could update it, and then later rerelease it, and I'm not sure if they improved it in any significant way. I played this, and it was a pretty mediocre game.
Then there's Mutants in Manhatten. Another 3D brawler, but this time from Platinum Games. This one hurt because 1) It's heavily modelled after the IDW aesthetic, with Mateus Santalucco providing the art and Bebop and Rocksteady sporting their chainsaw and sledgehammer. And 2) It's developed by Platinum Games, arguably one of the best developers in the entire video game industry. But it was clearly the C-team, and thus it's probably the worst game they've ever put out by a notable margin.
The game's a complete slog. It's a shame too, because it looks nifty, has pretty decent music, and there are highlights in the voice cast. In particular Robbie Daymond (the voice of Spidey in the Marvel's Spider-Man cartoon) is rather well suited to playing Mikey.
Of the Activision era, of the ones I've played (I have not played the 2012-inspired beat-em-up, though I've heard it's nothing special - kind of tempted if I can get a copy at a reasonable price) the best one by far is - you guessed it - a retro-style game. Danger of the Ooze was by Wayforward (one of the OTHER best devs in the industry, who specialize entirely in retro games) and was unabashedly a remake of the infamously hard single-player first NES game, with the key difference being no overworld map and clear level divide, making it a Metroidvania, and it's very much based on the 2012. IMO it's the good version of that game. It had a very strong attention to detail in terms of 2012 cartoon fanservice, and a musical score worthy of Wayforward's usual high standards.
None of this means it couldn't be done, and it would be very, very nice if they could put out a game like you describe. But all that in mind I can't blame them for going this route. It's probably way cheaper with a much easier chance of success and that retro nostalgia does appeal to folks. If the game plays as good as it looks, it'll probably be one of the best TMNT games in over 20 years. Which is kind of sad, but oh well.
