So... I'm confused. We're upset because a loving fictional relationship broke up and now we're upset that the relationship currently isn't abusive enough?
Long story short, the 80's saw the relationship becoming much more loving and less disrespectful after MTM. Coincidentally, the same time Jim was being far more experimental and essentially turning the Muppets into more kiddy fare (those Play-a-long videos), while focusing more on things like Labyrinth and Dark Crystal for older audiences. While I never thought he would abandon the cold, it seems that he wanted to close off that sort of relationship with the characters (at least until the Pig of the 90's thing that never happened). Meanwhile, the only place to actually see the show's complicated, semi-abusive Kermit Piggy relationship was...and take note of this oddity... Muppet Babies!
As a result some fans have the headcanon of Kermit and Piggy being married off in MTM. And for shame on the editor who cut that revelation out of TM where they broke up because of a fight over that. That's the kind of relationship everyone claims to be missing (but more on that later).
Now with the 90's and the relaunch, Piggy was pretty much barely there (and for the sake of the joke, Fozzie). We got a loving relationship in MCC (because they had to, they were playing characters), a complicated one in backstory in MTI (for the sake of putting the Pig into a movie that would otherwise not have fit her in if it went as close to the book as MCC was), NO relationship in MFS (and for that matter, due to Frank's lack of availability, barely present in MT) , back to the classic complicated dynamic in VMX (one of the best things about the film, honestly), then the "fans love to see them yell and karate each other" public appearances, then no room for a logical relationship in MWOZ, Disney flip flopping the heck out of it in personal appearances, some small relationship friction that gets easily resolved in LTS, and then we finally get some complexity (and in the case of the first one, maturity) in the two new movies...even though they chopped off the call back to MTM because 100 minute running time. Now this wrinkle.
Overall, face it. From a standpoint the "will they or won't they" was a nice aspect for the TV show, but after a while, it would have gotten repetitive. yet marrying them off would be boring. That's why the post-Jim, Pre-Disney Kermit/Piggy era was marred by Flanderization. They didn't get what made the TV show abusive relationship special, and they just tried a pallid copy of it. Disney started out that way, sure, but then it seems they realized the fans didn't actually like that so much, then tried to make them an official couple again, just before the announcement of the TV Show, where this is a major plot point.