I don't want to mention names because there are many. Most of them are probably coming from stake campaign. It seems like some of them are trying to make a post longer when it can be done with short post.
Some signature campaigns (like Stake's for example) have requirements on the number of characters that have to be in a post. So while they may have a very simple answer that could be given in a few words, they are incentivized with money to make their posts a little longer in order to reach the character requirements that have been set. I'm not familiar with how widespread this is with other campaigns, but perhaps that explains why you singled out Stake.
I think they should leave the Stake campaign out of this, there are many posters that write in such a way that carries a semantic load and not a summary like some people would want. Summary or not, it is at the discretion of the author, and me personally, I always try to limit what I post even though I have a lot to say. This is because it might be boring the reader if it is too long, but that doesn't mean that if I write more it will still not have more meaning, only that I might leave the rest which I need to discuss on another day when I visit the topic with a similar reply to be made.
It is a free world here and even with the Stake campaign, the campaigner would be paid so far it is up to 150 characters and I believe that should be barely two lines, so nothing is compulsory here. It could also be that some people like writing, just like me, and want to effectively express themselves in what they convey to people. I absolutely see nothing wrong in that even as it is better for campaigns as it shows they selected the right person(s) that can represent them well and not dullrads.