Abusive or not, I think such accounts/users are a reflection of our increasingly "entitled" world. People want things "now" without working for them, and they want "rewards" without putting in the time and effort.
Just look at all the "upvote services," as well. People send their 2 SBD, get an upvote worth $3.00, by the end of 7 days, the value has declined to $2.50, then 25% goes to curation and in the end... they paid 2SBD to "earn" $1.90. The only gainer in the equation is the already-rich "whale" who's running the scheme.
All we can do, I suppose, is choose to NOT participate in these things and then point to-- and promote-- our own successes as "a better way" to build success on Steemit.
Sadly, a lot of people want "money for nothing."
You are probably right, and we see this more and more on Steemit.
I did some tests with these services in the past. The net result is most of the time loss making. Some users explained to me they buy the upvotes to get a couple of dollars on their post so it looks better and they hope more powerful Steemians, or a whole bunch of minnows will vote because of the couple of dollars on the post. I think it doesn't work like that, since I think the more powerful Steemians do not vote on posts that got (a lot of) self votes through these 3rd party services.
Others are explaining me they rent SP for some time to gain more followers and hope to get more traction with their account and posts when having more followers. My own experience is that followers doesn't count at all, I have more than 1.300 followers and still get only a couple of votes on a post from others than those who support me for (almost) every post.
Those who have a follow base of more than 15.000 or 20.000 Steemians and offer their account for ReSteem, generally got me 5 to maximum 10 newbie / small account votes that for sure does not make up for the 2 SBD spend.
I suppose it is the low level of knowledge of many Steemians that causes them paying for all this nice looking service, upvote/Resteem or whatever.
For a little time, I used some of the services, time to time. This was more or less a test to see what actually brings value and what not. In the end, I decided to not use them anymore 1) they are direct loss making 2) indirect effects are hard to quantify, but have a feeling it does not bring the value in the mid to long term.
Somehow we need to educate the community. That may result in lower usage of all these paid services and remove the business case for the owners and managers of these services. But that will be a though journey. Not sure how to start, maybe we all should start writing posts about it.