I hated it when it first aired. Maybe I was overly harsh on it because I wanted so bad for it to be great. But the first two seasons were shit. I didn't like any of it until this year when I watched seasons three and four and enjoyed them.
There were just so many cringe episodes in the first two seasons. It was a show that took place in the 22nd century and the fourth episode had a holodeck. The second episode featured a woman figuring out an entire language, including vocabulary, by listening to it for a few hours. It went downhill from there, hitting its lowest valley when T'Pol taught a group of villagers that the best way to defend yourself from klingons is to duck backward twice then roll away.
Also the temporal cold war established that any 6th grader in the future can completely unmake history using the tools in his school desk, completely breaking any semblance of sanity in the Star Trek future.
The entire first two seasons of the series combined the worst of the forehead alien formula with pale misguided attempts to have the social relevance earlier incarnations of the series did, and to link with future precedents such as vulcan mindmelds, the prime directive and the Borg.
Then Manny Coto joined the writing staff and they remembered how to write, and the show got good.