One thing about reading comics set in a shared universe is different writers and artists have different styles and different takes on characters. This is not news. Some of those never go beyond the one who started them. I don't feel as though Mark Waid's take on Daredevil has gained a lot of traction, for example. Maybe it will down the line. Sometimes, what gets introduced sticks. Whether it's good or not depends on who you ask.
But if you aren't a fan, it's never a good feeling when you see other writers starting to adopt that version of things. While it's contained to that one book, it can be annoying, but hopefully easily ignored (unless that's the only book the character appears in). And hell, that writer or artist can't stay on the book forever, right?
Once it starts to take hold in other books, it stands a better chance of becoming the accepted norm. It's not restricted to a small corner any longer. It's spreading roots out and taking hold over a wider range. The more other stories that version of the character gets involved in, the more characters it interacts with, the harder it is to take it out, reshape it, or revert it to an earlier state. Not impossible, obviously. If we're talking superhero comics (and that's mostly what I'm thinking of here), you've got shapeshifters, possession, mind control, time travel, alternate universes, linewide reboots, all kinds of things to explain your way out of it. But it still requires taking the time to use one of those to explain it away.
I think I prefer the approach Marvel takes sometimes, where they simply don't reference a particular event in a character's history once it's passed. If you liked it, it can be disappointing to see it ignored when there are times it could or should come up, but at least it isn't being actively erased. Because then someone has to write another story countering the story that did the erasing, which gets kind of messy. And if you didn't like that particular story, well, it's being ignored by subsequent writers and artists, so they seem to agree with you.
But that gets harder the more widespread the event or characterization shift gets. It was relatively easy with, for example, the story in the '90s where Peter Parker's parents came back, only to be revealed as artificial creations of the Chamelon's trying to learn Spider-Man's identity. Granting that Spider-Man had a whole mess of books at the time to use that concept, it was still relatively contained. If the Spider-writers essentially kicked it under the rug and left it at that, there wasn't anyone else who had used it where it needed to be explained away. You get Cassandra Cain popping up crazy and evil and leading the League of Assassins in Robin, and Teen Titans, and Supergirl, it gets a little harder to revert her back to being a good guy without having to deal with the "how" and the "why" at least a little.
I don't have any big point with all this. It originally started as me being bummed out the Black Cat as a crime boss thing seems to be really taking hold, with Hellcat and Power Man and Iron Fist both using the idea, meaning it's moved beyond the Spider-corner of the Marvel U. But I didn't want this to be another screed about that development. So it turned into me musing on the nature of changes taking hold, and how easy or hard it can be to reverse them later.