a) The concept for the survey was indeed from whogotin.com. It seemed to me that the creator of whogotin (rocksee) had no problem with this, as she is aware of all the new sites using the concept.
There is a big difference between stealing an idea (and, as I said, in this case the idea was taken but it does not seem to me it was in anyway "stolen") and stealing a site (i.e. the actual HTML).. it's abundantly clear that meridionale didn't steal the site since gradcafe doesn't look anything like whogotin and the automated part of the survey was done from scratch by a volunteer.
c) While it's true that facts, like those we're entering into this site, are not copyrightable, what whoever is behind yuster did is still in very bad form. They may not have broken the law, but they did take data from this site when it was clear that yuster was less popular. The fact that they have pay ads does make one think they did this for their own profit, rather than for the benefit of those applying to grad school.
d) Not really relevant to this argument, but in my opinion Yuster made their site a lot worse when they started taking data from thegradcafe. The page for my discipline now has at least 1 duplicate for most of the entries, in some cases 3, which makes it much less useful to look at. I used to look at both sites but now I see no point in looking at yuster so I only check thegradcafe. So IMO yuster brought their unpopularity upon themselves and now they're just bitter that people are coming here instead.