Ill do my best to respond on my phone:
1 every consolr is good at different things. The advantage of multiplats are engines that easily convert the coding. The problem is that the code is not optimized to the system. Take a port from wii to ps3 the graphics wont be as good as possible and the control style would be hindering. That is why developing for one console acheives better results.
2 the problem with hardware war is this. Game revenues go toward console makers. 15$ per game goes there. There more systems the less centralization, leading to companies not being able to support the hardware as much. The thing is weve had hardware competition in the days before nintendo. It led to customer confusion and eventually a complete collapse. Nintendo changed this with the seal of quality. It promised great exclusive games.
the otger factor is that with different consoles, companies will continue to try and differentiate by having made their own exclusives. What you will eventually end up with is an even more fractired exclusivity rate.
And if there was only one console? Then someone would make a new console. Because the money is there, companies will always gravitate toward making consoles and developing exclusive games for them.
