Well of course everyone can do with their vote as they want but it seems to me that if this is all someone does then they are not likely to get follows or votes from people like you or me for that matter. Then the only votes they get are their own votes. U can actually get MORE money out of uprooting others than by uprooting your own posts simply because you can get support from a lot of other people by interacting and supporting to an exponential rate of which accumulates over time.
So just remember karma is real. People that help and support will at some point get that help and support in return. People who are just self absorbed will not have friends or supporters.