Depends on what you mean by "worth it". Worth just giving a try as a Trek fan, I would say yes, especially if you're a completionist. Worth it as in you're looking for a good television show, largely no. If you can make it through Voyager and even enjoy it, you'll probably not have that much of an issue with Enterprise, but the first two seasons are extremely painful to get through, and largely not for being laughably horrific or anything, but just for being dull, boring, somewhat embarrassing and childish and just plain head scratching. The first two seasons are apparently the product of both executive meddling (the original idea for Enterprise was nothing like what we got on screen) and just franchise fatigue and burnout on the part of the creators, Rick Berman and Brannon Braga, who given what they produced, showed they had practically nothing unique to add to Trek. When they take a backseat and let others write and produce for the next two seasons, things drastically improve, you get some interesting plots, some actual character development, some actual good acting here and there and the characters turn from being annoying, arrogant, smug, childish douchebags into half-decent crew members with their moments. Also the fourth season is, gasp, get this, actually a prequel to the Trek franchise, you know, the whole premise the show was supposed to have? Despite its flaws, I do recommend the fourth season if you're a Trek fan and can get over the characterization issues, there's even a few episodes I dare say I'd rank as among my favorite Trek episodes. There's a reason Enterprise isn't just completely rebuked but in fact some fans have a soft spot for it, it's this season. Not the absolute best, but good enough to not totally reject.

Anyway, that's my two cents.