Did I ever say that you "can't", as in "not allowed"? Yes, of course you can; I literally said that it's fine if you want to do it. All I'm saying is that I'm not personally comfortable with that kind of revisionism or "death of the author", that I find it artificial and can't take it seriously.
For example, I see people now trying to reconcile the portrayal of SNW Chapel with her portrayal in TOS, by explaining how she became depressed after Korby's death, and that's why she's more subdued now. And how her advances at Spock are due to her not being over their previous relationship. Okay, if you want to explain things like that, do so. But being totally honest, does someone REALLY think that was the intention with Chapel in TOS? The character wasn't written as a depressed woman or an obsessed ex. She hadn't been following her ex around for years. She just had an unrequited crush on this new guy she met recently, nothing else.
And this is the problem I see with these enforced revisions of the new material over the old material. They end up warping the characters in ways that were never intended in the original. They're not real people, they're fictional characters, so when the writers change, the characters will necessarily change. They're never gonna be 100% consistent, so there's no need to be constantly revising or retconning things to achieve "perfect consistency".
And going back to TAS, it's the same thing. The show is done, it has Roddenberry's name on the credits. Take it or leave it, just as it is. But what's the point in going back all the time to "correct" TAS or strike things out, according to the latest whims?
