I'm not going to suggest I know their motivations, just that they may have interests (ahem anarchy ahem) that aren't mine. Anything that helps people find what they are looking for is good for the platform. And any post that makes a boatload of money, well good for them! As long as it isn't 3 in a day saying 'hi I'm here' followed by 'thanks for the money' followed by 'no - really - thanks'.
I'm not saying it's good or bad, it's what it is. If I was a whale or an early bird I would do the same thing, free money forever. I would upvote newcomers who are minor internet stars so they can "spread the word" and keep the motor running.
I don't think that's really sustainable, maybe it is. Just like in real life, I personally don't like the "rich get richer" approach. In Steemit case if you really pay attention, the rich get MEGA RICHER. No dolphin have a single shot of passing an early adopter. An early adopter can post whatever she/he wants, there is a lot of evidence (a single photo from his vacation for example) and get 2k.