Intel has done will in the iOS department. The problem is they are still playing catch up with ARM in terms of cell, tablets, and other low power designs.
Intel's business is heavily focused on gross margins. Just look at how the stock tanks when it dips below 60%.
At Intel many of the foundry type applications are done when certain technology processes are being warmed down (machines have been fully amortized, processes have been stable and capable for years, and there aren't any breakthroughs needed to get the product built. They aren't getting the absolute best technical solutions, they are getting the lines, engineers, and equipment that are on their way out. That is unless Intel dealing with really expensive high margin product. Things along the lines of ultra-expensive corporate mega servers with huge die, innovative design requirements, or entirely new form factors (since Intel can provide both processor and motherboard solutions..
In fact some business units within Intel (think low cost consumer applications) have outside fabs manufacture their designs because it's more cost effective than tying up internal resources working on the more profitably next gen Core processors. Remember Xscale, Intel based designs based on ARM projects which were often externally manufactured.
Fact is most outside companies looking for a foundry, are willing to use TSMC or other lower cost (not necessarily low quality) fabs because their designs don't need the manufacturing complexity. Plus with the heavy commitments to internal customers (who represent billions of dollars in revenue), many external customers don't want to see their designs placed at the back of the queue.