[jacobolus]

There’s no “they” here, the “US Government” isn’t “concerned” about anything, and the Comcast/TWC merger is at the mercy of an enormously complex political process/system, not some singularly acting Feds who can “see fit” to do one thing or another. Anthropomorphizing an institution as big as the US Federal Government is dangerous, because it easily leads to reasoning about institutions as if they were individual people, but such entities behave in entirely different ways than individuals.

Anyway, with that digression out of the way, if you want to understand the relationship between government regulators and telecommunications companies, I highly recommend Tim Wu’s book The Master Switch. Government regulation of telecommunications industries has often been contingent, contradictory, and somewhat chaotic (in the sense that small nudges lead to dramatic unpredictable changes).