Summary: The AT&T/T-Mobile deal is actually a big win for T-Mobile's infrastructure (nobody is arguing that, I don't think). Author doesn't really establish her point about 'the industry' outside the speculative bubble of what this means for T-Mobile and echoing the article headline:

AT&T and T-Mobile deal has very little impact on the state of the wireless industry as a whole.

Okay, how? If this goes through, the most Android friendly carrier is being assimilated by the least Android friendly carrier, who will also hold the figurative gatekey to GSM with no imperative or motivation for improving GSM beyond scaling their infrastructure.