I didn't really mind the ending. IMO, the only lame part was the scene where Jack goes back to where the coffin was....it looked like they included like every single symbol from every single religion/philosophy out there so as not to piss someone off (I get it, I mean, they wanted people to get that "where" they are at is wherever your spiritual preference puts them, but IMO, if you caught that you wouldn't have needed to see those symbols to get that). Christian's explanation was good, I thought, even though it kind of spelled it out. I think Jack (much like most of the audience) needed to hear it. They could have done some vague'r dialogue, but if you're Jack, those questions (and answers) were suitable for that moment.
I just don't see how, after some reflection, people can't appreciate or see the parallels to real life that this show presented. They're quite profound and compelling.