What I'm curious to know is whether or not the fan community believes that Enterprise is the most hated of the Star Trek series (although I understand it is competing with Voyager for the honour) and why.
For me, despite running three seasons shorter, I think ENT surpasses VOY.
While ENT was obviously flawed in many ways, I do think a lot of the criticism is unfair or unfounded.
ENT tried a little bit of everything. In its first two seasons it wanted to simply be a "Star Trek series set in the 22nd century" without necessarily feeling obligated to focus on tie-ins to TOS all the while following the TOS/TNG formula. It was more about showing the first crew going out into deep space and how their reactions were different from future crews. I think this might have been a mistake because they thought they could simply take an old chestnut from one of the earlier shows and having a new crew process it would alone make it interesting.
Instead, in a lot of instances it felt like we had already seen a particularly story before on another Trek series and was done better. That isn't to say that the first two seasons were a wash. There were plenty of interesting if well worn stories(most written by Mike Sussman and Phyllis Strong)--Broken Bow, Fight or Flight, Shuttlepod One, The Andorian Incident, Fallen Hero, Carbon Creek, Minefield, Dead Stop, The Catwalk, Cease Fire, Future Tense, Regeneration.
Many fans felt that ENT needed to be more arc-based. I think a case could be made for that but I actually felt ENT's problem was more because of writing and not format. Still, no one can really deny how the Xindi arc energized the series.
I thought season three was a vast improvement over the first two seasons and was the next identity the show sampled following the standalone TOS/TNG format. Looking back it was one of if not the first series I watched that experimented with the style that Lost and Heroes uses--throwing a bunch of questions/mysteries at the audience leaving you scratching your head as to what is really going on and who is telling the truth. It really did try to forge its own identity here without relying on Trek staples by introducing the Xindi, the Expanse.
It also added some important elements sorely lacking from the first two years--mystery, interesting plots, twists, suspense, thrilling action, fatalism, a darker edge and jeopardy.
Then season four comes along where the series once again dabbles with a new format/identity--embracing the prequel premise. I really enjoyed this season and felt it was the most consistent. I think a lot of fans enjoyed it so much because it didn't require you to like the ENT characters because they were secondary and the stories they told added some rich backstory to the Trek mythology. So if you were a big Trek fan you'd be interested with the new insight or intriguing take by the writers on what happened in this era you might not have expected.
So I really think the Xindi arc and the season four stories really elevated ENT above VOY.
Another aspect of my research seems to point to the fact that Enterprise appeals mostly to people who were only mild fans of the other series, or who were never really "into" Star Trek in the first place. Does this ring true to you all, or not?
Somewhat. I have seen some TOS fans say they gave up on the 24th century series and ENT brought them back to Trek. Others love all four pf the previous series and hate ENT. I've seen some say they love TNG and ENT. Some say it is as good as DS9. I think it is hard to say for sure. Personally I watched all five shows. TNG is my favorite followed by DS9/TOS then ENT then VOY.