No, people are voting on "sure shots" because they don't understand the curation rewards.

This post is a great example. 94% of the curation rewards are going to Dan. At the current post value of about $2000, that leaves approximately $30 curation rewards total for everyone else, with the earliest high-SP voters getting most of that. The later voters are getting virtually nothing to literally nothing (I believe many will indeed round down to zero and not be paid at all). If you voted for this post hoping to get curation rewards, you wasted your vote.

While the details may differ, all of the high payout posts are essentially the same. The author and early voters get almost all of the reward; people voting later and who are the ones boosting the rewards to the stratosphere are getting little to no curation rewards in return.

There is often a lot of piling to a relatively small number of posts, I'll agree with that. But the reason is not the curation rewards, it is something else.