I loved the ending of the finale. I respect people who didn't like it, but I am just not one of those people. The show always went back and forth between science fiction and a plain drama. The first 3 seasons were mostly drama mystery, but when they moved the island in season 4 it became completely science fiction then in season 5 they started with the time travel again science fiction. This is when I became upset with the show but no one else did I felt like I was the only one.
Over time I was able to accept it, and really just focus on the characters and what they do to handle these supernatural problems. So yes I followed the characters not the mysteries. The mysteries made the show more intriguing for sure, but that's not why I watched the show in the end. This is also probably why I liked the ending since it was completely character centric.
As for reasons people dont like the ending you guys have given many and Ill try to address some.
They didn't give enough answers is always the general complaint. They actually answered most things there are a select few things left unsolved but to be honest I thought 90 95 percent of everything was addressed. It really just felt like people didn't like the answers they were given. Which is fine, but I don't know what people wanted. As Andy Kaufman/Jim Careysaid the crowd is expecting so much so short of faking my own deathor burning the theatre down I don't know how to surprise them. I was completely satisfied with the answers. I think people wanted the Lost writers to tell us where humans came from lol and that just wasn't going to happen.
Saying the show did not hit the appropriate genre with its male audience is ridiculous. Sorry, but the show primarily focuses on guys it became all to obvious the only female they could write for is Kate. You don't have to be in touch with your feminine side to enjoy a happy ending for characters you have been rooting for, for six seasons.
I really respect people who didn't like the finale because I hated the show so much during season 5, and I felt like I was the only one. Luckily for me I adjusted my outlook on the show and became OK with it. Its hard to become OK with something that's ended and you get no more of it. I have tons to say on the subject but this post is to long already lol.
And for the record the nuke set off by Jack/Juliet in season 5 finale is what created purgatory. That was very clear and obvious. And all the island stuff did happen again also clear pretty sure Christian flat out says it. (for anyone who wasnt sure)