Finally, there's the fact that effectively delivering infrastructure is a different challenge than, say, delivering applications. Telcos have decades of experience in delivering infrastructure. They're not the only ones -- companies such as IBM, for instance, can say the same. But they've got certainly got the experience.
All that said, the telcos also have a track record of making unbelievably boneheaded moves, so there's no guarantee they'll pull this one off. As I said up front -- it's their game to lose.