I don't want to claim that the airburst is not strong, but to be honest in that example the circumstance of a massive stupid blob of Sturmtruppen got punished very hard.
Let's imagine that there would only be one squad in the AoE: In the end we would just see 3-4 dead bodies.
There are some more problems then just the airburst.. .
Whereas I do agree that every massive blob should be punished, but I'd also like to point out that it's not a mortar, which should be able to do such punishment. Don't forget that they were ALL MAX HP. As for your last sentence / argument: it is pretty stupid... It's not the amount of kills that really concerns me but the fact that it can instagib full hp elite infantry from 1 round, and it's not even necessary for the infantry to be standing on a mine, like in elitegren's case...