From what I'm reading, a yellow + a blue is still a red. So in the situation where a player already is on a yellow, where the ref might be reticent to issue a second yellow, a blue would effectively be exactly the same.
Although I agree that particular situation (player on a yellow does...
What also annoys me about those is when the commentator will say it was a "good foul" or that the offender "had to do it". Should give those commentators a blue card which comes with 10 minutes of STFU.