It's success was more around its character development and the setting. It set up a lot of things that looked like they'd be used later, but while there were seasons left, people actually gobbled it up. Then the author/writers realized they wouldn't be able to tie up all the loose ends they left, and definitely not in two seasons, so it was unsatisfying. It also meant they were tying up loose ends and not spending time on the character development that made the show.
Yeah, I still love that show and will recommend it to people who haven't seen it yet (or at least to fans of genre fiction like that) but it was frustrating for sure.
Speaking of Lost, I re-watched it with my SO last year because she had never seen it. It's weird how so much of the format has become the standard for network TV drama/adventure/mystery/scifi shows. There were multiple points where she just didn't see the big deal and I had to point out how there just weren't many shows that did things like this back then.
I checked TVTropes but it's not on the list of "Seinfeld is unfunny" examples. Same concept though.
