If this is an example of a "broken" power, then;
A) 4e is just a Poo game to start with,
B) your specific game is poo.
Possibly both, but definitely at least one of those.
I'll assume you think it's broken because of it being a great way to sweep away those 1/low hp minions?
So, if your players are taking powers like this for that reason, then the DM needs to get the message.
And that message is....
Stop wasting your players time with low hp minions. No one feels heroic when all it takes to kill the monsters is a single point or two of damage.
So try improving the game your running instead of nerfing powers like this & making dealing with minions even more of a pointless slog than it already is.