Grivahri said:
I was going to write a reply explaining why I thought Far Cry 3 had a pretty damn good ending. Cutting it short, however, I believe that the ending achieve two things: it wraps up the dominant themes of insanity, freedom, tribal mysticism and growing up, whilst also leaving questions inside of the players mind which they can later think about. But in its full form that would have taken too long, so here's a few responses to some of the questions you raised.
Why did the Rakyat suddenly go crazy? At the point in the main campaign when this happens, Citra believes that you are essentially the second coming of the Warrior God that slew the giant ink monster whose corpse, which Rakyat tradition dictates, created the Rook Island. Your victory over Vaas, Buck, the poison and Hoyt are the things that prove to them that you are this God, trapped in mortal form. Not only this, but when did the Rakyat ever suddenly go crazy? They always were, the carried around AK-47's and went around killing pirates, led by a mystic 'Warrior Goddess' whilst following ancient tribal traditions. Dennis is the perfect example of this, at the start of the game, he is made to appear like a hero standing up for his people - Jason eventually discovers otherwise, however, first when you see him drunk after the ceremony, but also how he appears in the good ending - he's absolutely batshit crazy.
Why did they kidnap your friends? This is because of the whole tribal mysticism aspect of game, and is revealed in greater depth by the bad ending - Citra and the Rakyat believes that you are a Warrior God trapped in mortal form. The only way to 'free' you from your earthly ties is to first cut that which binds you to the mortal realm, and then to destroy your mortal body, allowing you to ascend to God-knows-where.
Why were your friends still there? This much isn't actually explained in game, and can easily be seen as a ploy to help the plot potter along. Then again, at that point Jason has already cut his ties with them to delve deeper in the insanity of life on the island, so why should the player, as Jason Brody, need to know there thoughts and reasons for staying? It shows that things are happening outside Jason's knowledge, which is actually quite realistic when you think of it.
Why can't they take it easy and celebrate Hoyt's death? This is mixture between the mysticism and the insanity - Citra is most definitely in love with you and believes that you are suffering whilst trapped in your mortal form, and therefore would organise the Rakyat ceremony as soon as the Island is safe.
Why don't we get to see what happens after the ending? Because that'd totally ruin it! They supply the reader with just enough to allow them to imagine what could happen to Jason following the psychologically traumatic events on Rook Island - he's obviously in a seriously dark place, so whether he becomes a deranged serial killer, works hard through psychotherapy to live normally, constantly trying to suppress that thought that things were so much...more on the Island. The good ending supplies what it needs to, and does it in a clever way.
Why is Dennis only there for half a minute? IMO, Dennis' disappearance from the plot symbolizes Jason becoming more important to the Rakyat, and crucially Citra.
The difference between the good ending and the bad ending is that in one you accept childish insanity of the Island and its traditions, you choose escapism over the much harder to live with reality, the thing that Jason has constantly been avoiding, as demonstrated by his bio of 'drifting' through things, signing himself up for death-defying, adrenaline-junkey endeavors. In the good ending, you accept that the freedom offered by the Island is a fake one, Jason accepts that this is not life, that human life has value, that order is there for a reason against anarchy. That's the short of it, at least.
What you seem to consider a 'good ending' is one that fully wraps almost everything up, ending with a memorable but entirely gratuitous image. Don't get me wrong, this can definitely be really cool - Halo:Reach is a great example where such a thing works really well. But Far Cry 3 is a different game, with different themes underlying its plot. I think it does its job well.
Hope that helps a teensy bit at least!