Based on Microsoft's recent decision and some other rumors ARM on server might reduce Intel to only 90+% over the next few years but that's nearly the same cashflow.

They didn't miss mobile. Mobile makes poor margins at least for intel so they are not in it. PC sales are already down. Where they make a ton of their money is data centers.

They did. They invested a lot in R+D on mobile processors.

Mobile chips is low margin, there is hardly any money in it anyway.

That's right, but then when did they spent so much on mobile R+D?

Partially because they felt they could gain some advantage by owning the client side of what is powering a lot of their data center chips. Investing in modem tech and trying to get into mobile phones, they could have a completely integrated story from the phone, modem, cell tower (see Axxia acquisition), to the data center. I think they also were hoping the Intel Security story would be compelling from an end-2-end perspective.

Mobile really means lower power and more integrated functions. Those aspects are becoming more important for all applications.