If you have enough Steem Power and you select content that is popular you may even earn some Steem

I'd reword that to select content that becomes popular. I just received 3.332 STEEM because I voted quite late on a new member's art post. I had no way of knowing that post would become popular over time, as more actual curation occurred after my efforts. So that was a nice bonus.

I still don't mind voting late, like I did here on your post. I voted late quite often before the hardfork. Even if I do that now, I'm still earning more than before. Once a post hits about $10, my vote is full force, rather than of lesser value until more votes roll in. We're not being penalized when voting late, we simply lessen the odds of hitting that curation lottery win like I had received today. Seems reasonable to me.