Your reasons are all pretty much covered by phone and tablet versions- the former most will have so why would they develop for a platform where they have to a) pay to develop a new version b) share microtransaction sales with Nintendo?
It makes no business sense at all. Particularly as the only reason we have a PC client is so there is a version that funnels all microtransactions on that client to EA, and not to reach new fans. You can't really reach more fans when your game exists on the 2 most common platforms currently in existence in iOS (estimated 1 billion users) and Android (est 4 billion).
In the long run its definitely not worth it.