It's not that the series finale of Lost was "bad," exactly, so much as that it was the worst imaginable finale for the show and perhaps one of the worst of all time, including shows that ended with unceremonious cliffhangers after sudden cancellation. It's one of the infinitesimally few examples since I started following popular fiction around 1989 that the theories and endings that random schmucks on the street came up with turned out to be vastly superior to the real thing. James "Sawyer" Ford himself would be proud of the con that Lost pulled off; a pulpy soap opera that successfully masqueraded for years among critics and awards shows as serious television.
The Lost faithful will continue to whine and wheeze and gnash their teeth at anyone who points this out, of course, but it's all good. It's hard to believe today, but some of you might remember that back in 1999 when The Phantom Menace came out anyone who set a critical foot into any Star Wars message board was chased out with pitchforks and death threats. Some fanboys literally took years to admit the truth. Lost fans are struggling with their disappointment the same way that Star Wars fans did a decade back, but it's cool, I'll wait for them. I have no problem being ahead of the curve.