The Liberals may be forcing an election soon, and after tens of thousands of complaint emails, the decision was an easy way to gain a couple percentage points in the polls. This was a no-brainer for the incumbent Conservatives, but their swiftness in resolving the issue was really impressive.
They weren't particularly swift. Every other party had come out strongly against UBB while the conservatives would only say they would be "paying close attention" to the ruling. This was simply such a wildly unpopular decision that it would have been political suicide to support it, and once every other party had come out against it the Conservatives couldn't be the only ones not to do so. The Conservatives are well-known for being anti-regulation and pro-big business, which aren't very popular sentiments in most of Canada. They couldn't afford to wear this albatross around their neck.
They could not come out against it before the ruling was made. They are the gov't, and the CRTC is an arms length agency. It's not the government's place to interfere with an arms length agency, at least before they've announced a decision.
They weren't particularly swift. Every other party had come out strongly against UBB while the conservatives would only say they would be "paying close attention" to the ruling.
Opposition parties are always quick in reacting because there is little to be lost. They get zero credit for that.
This was simply such a wildly unpopular decision that it would have been political suicide to support it
Again, let's be rational here- the UBB decision impacted a very small number of users (although its competitive impact may have been larger over the longer term). Further there is a political risk in taking action like this in that now the opposition has the ammo to say "Well can't you let the experts do their job? Isn't this what they're supposed to do?" (see also: Census).
It isn't as clear cut as you proclaim at all. Now Bell can intentionally cripple their pipes for a bit, blame bandwidth hogs, and the Consveratives will be in hot water.