All are fair points and probably closer to the truth and Bungie has to walk a fine line with this game as their relationship with Sony is a new one and they have had a really good relationship with MS for much longer.
Facts and good business decisions aside, people know there is a power difference between the two consoles. PS4 owners, as with any console owner, want to see the best product possible on their system at all times. This is why the whole "console parity" issue came up once the hardware specs were actualized and everyone know there was more power in the PS4. Obviously, 1st party titles will utilize that extra power, but the majority of people that buy 3rd party titles for the mostly and choose a PS4 because of the game ratings thus far on PS4 have been better, expect the PS4 version to again perform and look better. Then take a look at the marketing agreement that Sony made with Bungie to promote the game, again, you can see why people expect there to be a difference uin the two versions.
Again, relationships, dev. costs/decisions aside, there will definately be questions why they choose parity instead of opimization for the game and you can understand why, people want the best version possible for their system at all times, and this obviously wasn't it, even after the launch delay.