Every system is gameable to some extent. It seems, at least from my perspective, harder to game rep than SP. Plus it gives the community a way to diminish the VP of bad actors. There's no way currently for us to actually reduce the SP of someone's account (nor should there be). The goal is, of course, to give the community the tools it needs to moderate itself better, and to make gaming the system less productive than just participating. Over time you iterate and patch the things that aren't working as intented, like any program or system.