They have actually frequently said that ENT wasn't perfect.
That is hardly a real or sincere or even a mea culpa of any kind. First and foremost, nothing is perfect. A generalized statement that Enterprise was flawed is a statement of fact not a reflective acknowledgement of culpability. It is a non-apology designed to deflect.
It's almost like pleading "no contest" wherein they concede Enterprise failed, but refuse to say anything specific that could be construed as the failure being the result of their stewardship.
I saw the first two years of Enterprise in first broadcast, and realized it was in trouble early on. This impression is not due to fan reaction as I wasn't heavily active on fan sites like this in those days. I was watching Star Trek since 1966, and all the shows have elements I didn't care for.
It's funny, in the beginning I was actually a defender of Enterprise. Back on AOL's Star Trek forum some blasted the very notion of a prequel series and those critics were made even more skeptical by Berman making Brannon Braga the executive-producer.
My position was simply the prequel premise was sound enough in principle and could easily work in practice. As for Braga, to my mind, new series, clean slate. I gave him amnesty and a fresh opportunity to impress.
Enterprise, like the other modern era Treks, started off weak, but after season one was over I assumed they would do a postmortem for the purpose of making the necessary changes. Sadly, season two started off weaker then the previous season ended - It was actually getting worse and not better! By mid-season I was done.
So, in my case, Enterprise drove me to go from champion to critic wherein Berman and Braga were the navigator and driver of that shuttle. I probably would have stuck with a mediocre Star Trek series, but Enterprise, to my surprise, fell short of even that low bar.
It would admittedly be hard to forgive and forget the damage done by Berman & Braga even if they did give an honest and heartfelt mea culpa (with specificity),but it is impossible without it.