I agree with most of the comments above. I'll add a bit of my own thinking...
In theory, ENT should have been more closely akin to TOS than the other ST series. Many TOS fans have been fans for decades. I think (without much established canon) fans had years to form their own pre-conceived notions of what pre-TOS is/should be like. ENT didn't always fit what had become semi-canon from fandom.
And yes, much of ENT seemed like a rehash of the usual Berman-era ST re-dressed in new trappings. Much of ENT could have easily passed as, say, any VOY eps rather than being something new and unique to ST.
Wasn't so much bad as it was just more of the same old, same old.
ENT missed a great opportunity to do ST that hadn't been done before, establish new canon history and create new ST mythos.