Yet the first personal rejection I had, advised me not to "mix" genres in urban fantasy story, because it threw off the story. Which confused me, since there was only one genre (urban fantasy) and the only thing that might seem like a different genre was the inclusion of a solar panel (which happens NOW and is not a future concept but

Then I had a rejection that said "Unfortunately, I'm going to pass on this one. There are some interesting concepts here, but the story didn't quite work for me" Which excluding "there are some interesting concepts" is a pretty standard form rejection. But is the "interesting concepts" just apart of the regular form? Is that meant genuinely?
I know there's not like a little button people press that says form rejection or personal, but I heard a few people say when they give form rejections they just copy and paste, so it's possible there's something "nice" to say that's still not meant personally.
Basically, what does a personal rejection really mean, and where is the line between "generic personal" and "giving critique because the story was really close but not quite." How can you tell what's a higher tier form or not? Is everything a guess?