Shitcoining on bitcoin has existed for over a decade and isn't going away. OP_CAT doesn't uniquely enable anything more, its just a scripting proposal that enables covenants and lots of other stuff.

Current bitcoin is moving towards custodians as scaling solutions which is the opposite of what we should be doing. Covenants are a good option for trying to scale this and OP_CAT is probably the most general covenant we could get.

OP_CAT was removed from bitcoin because there was no limits on it, that could have caused DoS vulnerabilites. Bringing it back with a limit (or with GSR) would be great imo. I don't think bitcoin would be dead if satoshi instead added a limit to OP_CAT instead of disabling it.