So his position seems to be that either these services should provide native clients for these platforms, or else they should expose APIs to let third-party dev

So his position seems to be that either these services should provide native clients for these platforms, or else they should expose APIs to let third-party developers create native clients. That's still not a position I'm comfortable with. (I wish everybody exposed APIs to third-party clients, but I understand how hard that can be.) On the other hand, it's a lot more reasonable than unconditionally forcing devs to port their apps over.