Well I suspect a lot of people would been more accepting of ENT's continuity problems if the writing had just been a lot stronger, and not so painfully cheesy and derivative (and seemingly aimed only at teenage boys). I think that's what makes the biggest difference for most fans.
Except that the "true" TOS fans were just as hostile toward TNG when it came along. Granted, it took a couple of seasons before it started getting really good, but some fans took even longer than that to accept it. Quality can help overcome the initial resistance, but the resistance is going to be there as a kneejerk reflex anyway.
Even I'm not immune to it. When I got the assignment to take over the post-series Enterprise
novels and went back and rewatched the series, I found I liked it a lot better the second time around. The first time, I'd watched it through the filter of "Oh, that's not what I expected"/"That's not what I would've done," and that colored my view of it. But when I came back and just accepted that it was what it was, took it on its own terms rather than weighing it against my preconceptions, I found it had a lot more merits. Oh, it definitely had its flaws and its failures, but a lot about it worked quite well for me.