There really not much point in making an option for player two as Dolphin still suffer from extremely slow (depending on which version you use) and erratic framerates. Not to mention that the emulation of the games themselves is quite a ways off , despite showing graphics. So when even the single player experience is hampered quite a bit, there no incentive to make way for player two until the emulator gets better and more optimized, plus PCs get faster in general as well.