Yet by your own admission you have not watched the show on a consistent basis.
You may have me confused with someone else. I watched "Enterprise" devoutely for the first season and a half (or two-thirds) - about 30% overall. And no one can credibly claim that wasn't giving the series' or specific actors a chance to impress. I watched more than enough to give a valid and justified critique. Of course, that to is my opinion.
I would also add that, generally speaking, even most of those who profess to like "Enterprise" qualify their opinions with it not really finding itself and getting traction until season four. That means even they were largely dissatisfied with seasons one through three. Which translates to one out of four seasons (25%) success rate.