With Subtle Strike, you always pay 1B and can get both effects: Give a target creature a +1/+1 counter, give a target creature -1/-1 until end of turn, or both. With Borrowed Malevolence, you only got to get +1/+1 on a creature. The counter is much more permanent.
Not only is this a decent combat trick in Limited, but it can be pretty good in Pauper on Magic Online. It wasn't quite good enough for Standard, but it's good value for only 2 mana on a common. I'd definitely use this in a Draft or sealed pool, that's for sure.