I know what you mean, there was a lot of shameless promotion and merchandising that was inevitable with a successful cartoon series, lol. Still I just can't say a bad word about the '80s ninja turtles, hehe.
I just felt like the newer TMNT cartoon was a bit too serious. I mean it felt like Raphael's whole character was "Grrr I'm angry" which really got tiresome after awhile. I mean like Nostalgia Critic said, "Remember when these guys were fun? Lighten up!"
The thing that bugs me is this... watch the live action movies. Raph was like that there. I'd say they took a movie movie adaption like direction, similar to how Batman TAS was similar, but not quite the Tim Burton movies (that one even used the film underscore for the theme song).
Again, I love both equally, but I think 2k3 had some better concepts, more time with Usagi Yojimbo (which really should have lead to a Usagi Yojimbo series), a superior version of Baxter Stockman (Insane in the Membrane was one of my favorite cartoons EVER), and of course, Casey Jones was a more important part of the series (the 80's series totally wasted the potential in having him show up every so often... he was only in 3 episodes, and he really was able to shine in Corporate Raiders from Dimension X). And, I gotta admit, I like April better as a scientist/older sister figure for the turtles... especially Don's babysitter crush on her.
But make no mistake, I'd throw them both under a bus for the comics. You know when they say a movie's good, but you need to read the book because it's better? Track down the old comics... you won't be disappointed. And, I have to admit, the Archie TMNT line was amazing. It used the 80's series as a model, but did much deeper stuff when it stopped copying episodes of the show.
But you know what franchise REALLY got killed by it's own 1980's legacy? The Smurfs. I've been reading the comics, and all I can say is the cutesy, adorable, always get along Buddy Bears aspect was never present. These rowdy bunch of Smurfs beat each other up, and they never held back on Brainy. Much like the mighty Gauls of Asterix fame. In fact, I think they established a few tropes there that the Asterix writers used. The Smurfs's distaste for Brainy is almost exactly the same as the Gauls for Cacophonix. Not to mention the Smurfs snacking on sarsaparilla leaves, and Gargamell wanting the Smurfs, not for stew, but to use to make a philosopher's stone. I'm enjoying these far more than the show. Too bad the movie script writers didn't bother doing any research.