Mobile water companies
To me, a mobile operator that still wants to provide data services (as opposed to connectivity) is rather like a municipal water company that decides it wants to be in the bottled mineral water business.
They see Evian and Fiji and they say to themselves "Hey! These guys are making a fortune in a business we ought to own. We know water. We HAVE water. We have trucks, and distribution, and customer relationships. Even more, we have a brand that consumers trust. Why would you trust water from a company you've never heard of- we have a huge advantage!"
So they hire McKinsey to do the plan, and Wolff Olins to come up with a brand. And two or three years later they launch the new, trusted, approved bottled mineral water. And the first bottles arrive in the supermarket and are put on the shelves next to the other 40 brands. And pretty soon the guiding execs leave (bio: "successfully delivered global launch of...") and the whole project is quietly forgotten.
Now, there are of course all sorts of problems with this analogy, but the key point is that something can look like it's an adjacent area when actually all of your skills and leverage points are irrelevant. Mobile operators have almost none of the skills and leverage points needed to be relevant for anything other than connectivity.
Indeed, one by one all of the factors that mobile operators thought were their unique advantages have gone away. Location went to GPS, payments to iTunes and Google (though operator billing still has a place, especially in emerging markets), identity to social networks (though the PSTN number often still plays a role in that), and the whole locus of innovation (and of lock-ins) has moved up the stack to smartphone platforms and the apps that run on then. Attempts at innovation by mobile operators, such as WAC, JOYN or the laughable Firefox Mobile partnership, are not so much flawed as irrelevant: it is simply not their role to play in this space.