Because its cheap as hell and have good AT potential for its tier, allowing it to win with units that cost 2-3 times as much fuel and in theory have better gun*cough*greyhound*cough*?
I think it just needs a more dedicated role and should get a proper cost adjusment then. But honestly I have never seen a 222 win against the Greyhound (probably because the commander isn't played all that much ^^) but I think it is okay that it packs a liitle punch against those vehicles.