Q:  Why did ATT attempt to merge with T-Mobile when there were huge anti-trust issues?

A: Their lawyers encouraged them because they could make a lot of money in fees whether the merger went ahead or not:

But the advisers that AT&T’s board were listening to most intently were the lawyers who would be on the front lines of the battle: Arnold & Porter and Crowell & Moring, which worked the antitrust strategy in Washington. (Sullivan & Cromwell worked on the deal mechanics.)

Those firms all charge by the hour, so the cynic — or skeptic — might suggest they had every incentive to push the deal ahead.

According to people involved in the decision-making process, the lawyers put the chances of success at 60 to 70 percent.

For AT&T’s board, that was a chance worth taking. The question they now must ask themselves: would they use those lawyers again?