Well, the only reason that is valid for a game that was finished being delayed was because it was getting ported to other platforms, and since there is not going to be extra content in any version of the game, it's pretty simple to deduce that Microsoft's development agreement is the reason why the game had to be delayed. For a developer, I can understand that they wanted to maximize the profits of the game, but I don't think pissing off thousands of people was a wise idea either. You kinda have to pick your battles as a developer I suppose, but giving certain platforms special features really can entice players to buy one system over another.
We don't try and call it the console wars for nothing, it just seems really asinine and irrelevant to have 3 platforms by different manufacturers, two of which are offering traditional gameplay over alternate control styles, but all 3 are getting effectively the exact same games all at the same time aside from one that has different controls. Exclusive games are pretty much non existent unless you are a Nintendo fanboy, even Sony's ability to pump out first party titles has diminished greatly over the years (probably a good thing, rehashing games every year is boring as hell!) and I don't think that Microsoft's next generation system is going to do as well sales wise as the 360 has because it relies too heavily on one single first party franchise to sell systems and then a whole whack of 3rd party titles to keep moving some units. While Nintendo's own 1st party development has slowed greatly too, they also have a massive amount of studios and teams working on parts of their projects at any given time regardless of what system they are making a game for, and that in itself can be an advantage for the Wii U. Their willingness to try new franchises or revitalize old one's is also what keeps people interested, Sony and Microsoft really don't take those risks.
Because monopoly is a good thing?
Competition is good. If one single entity controlled all the gaming then they'd set all the prices, all the norms for hardware, everything. That's a terrible thing.
Also while yes, the three consoles get the same multiplats, they each get their own exclusives and have their own features, pros and cons.
On the note of Sony first parties, pretty sure they pumped out plenty this generation than the PS2 one, especially with the PSP coming into factor.