Personally, I don't think reputation matters much on the platform. It's just a number. A high number might mean a strong reputation but a strong reputation for what? Good? Bad? The number doesn't say.

It's the same in the real world. I have a weak reputation because not that many people know me while Donald Trump has a very strong reputation because everyone knows him. Whether our respective reputations are good or bad has nothing to do with the strength of them.

So vote buying to increase reputation is meaningless. What matters is whether your reputation is good or bad to those who know you. Or, whether you can project the kind of reputation that you want. Of course, I suppose some users will be swayed by the reputation value.

In any case, I don't think increased reputation is why people buy votes. It's money. People buy votes to make more money. And that, to me, is the issue with vote buying on Steemit.