What we've seen here is that there were more studio politics, UPN probs, and so on that caused the cancellation rather than quality, which ENT was at it's zenith with in season 4. This is contrary to the oft repeated mantra that ENT sucked and was cancelled for it.
The only reason ENT was cancelled is because it was an expensive show that a lot of people weren't watching.
Don't let Braga fool you. Sure there was studio interference, but the producers and writers were still responsible for the quality of the episodes. I have no doubt that the studio gave some incredibly stupid notes to the producers, but that doesn't change the fact that B&B had no plan whatsoever for the show and the first two seasons were pretty much a pointless waste of time. I highly doubt that the studio gave notes like "We demand an episode were Trip gets pregnant" or "We'd really like to see an episode where the crew gets infected by dangerous alien pollen!". Of course they didn't.
As for the "critically acclaimed" fourth season, it's nothing more than a collection of poorly developed premises spread out across multiple episodes for budget reasons (why build sets for one episode, when we can use them for three?). Some worked (The Vulcan and Andorian arcs were quite entertaining) but most didn't (Augments? Klingon forehead mystery?) and the stand alone episodes were crap as always (Bound! These Are The Voyages! *shudder*
). The overal poor quality is why people (like myself) stopped watching this show.
Of course, I haven't seen the extras on this set yet, but I am very curious if Braga can not only point out what didn't work (which isn't hard and something fans have been telling him for years) but if he can tell what his original plan was for the show and why he couldn't convince TPTB that this plan was the way to move forward.