What the OP is missing in its "today" analysis is that that cloud platform are choosing nvidia right now since its the most mature compute platform, and so the

What the OP is missing in its "today" analysis is that that cloud platform are choosing nvidia right now since its the most mature compute platform, and so the software for using GPU on the cloud will be written more and more in cuda / using nvidia libs: it will become a defacto standard, and nvidia will entrench themselves that way.