"...Tom Wheeler, appeared open in 2011 to letting wireless giant AT&T Inc. acquire T-Mobile USA...But he had a price. In exchange for a $39 billion merger, AT&T would have had to agree to a slew of new regulations, according to an idea Mr. Wheeler laid out at the time on his personal blog."

If you dig into said personal blog, you can find the following article [1], where Mr. Wheeler summarizes his reasoning:

"Now we have the perverse situation where a government win means less regulation while a victory for the corporate interest opens the door to more."

It is clear through his explanation that his approval was meant only as leverage for harsher regulations on the duopoly of wireless TelCos. That is a pretty solid indicator of where his allegiance lies. Likewise, if you meander around his blog, you'll see lots of musings in favor of Net Neutrality.

[1]: http://www.mobilemusings.net/2011/09/awaiting-final-aria.htm...

Industry incumbents frequently use lobbyists to create regulation to raise the bar to entry in their field, cementing their own position and stifling competition - creating the kinds of complacent mono/doupolies that we know so well from cable companies and ISPs.

As for why they have become complacent monopolies: that is the nature of telecom (natural monopolies). There is unlimited economics of scale, so the most efficient state is E.G. For Verizon to keep growing until its the only wireless carrier.