Sometimes... sometimes no. I know a lot of people and bots do. If something is new, is already getting votes, chances are its curation is going to be worth spending vote power on insteads of a dead post that gains no traction.
I personally like good content. I notice a large number of curators gravitate towards posts that are already earning something.
Funny enough curators would earn more money that way, but in reality everyone goes for the trending ones and make fractions of the rewards, take away rewards from neglected authors and over-reward trending content in the process.
It's a mess currently :)
I just wrote a proposal in my latest article Curation problems (incentive, rewards and self-voting) to increase the incentive for curators and reduce or even eliminate self-voting.
I would even go as far as to distribute 10% to authors and 90% to curators.
You mean exactly like now? :)