It may not necessarily be because they don't qualify.
Suppose they're from an island country (say Jamaica) and just simply couldn't provide documentation for a 6 month gap even though they were in the country. After all, it's not like they can swim to Jamaica. lol

Remember, a lot of the people are young therefore they may not have a lot of stuff in their name like bills, bank statements etc.
Plus a lot of immigrants live in the shadows and don't like having stuff in their name that can be traced back to them. In a process like this which came up out of the blue, it may end up hurting them.


But anyway, my central point is just because a person got denied doesn't mean they applied maliciously or attempted fraud. I'm sure no one wants to piss away $465 knowing they don't qualify.