dude tell me about it. Most applicants I've met are cool, or at least just ok people. Most will kiss ass a bit or act a bit fake, but that's expected.
However, I've met some people who are seriously overly obsessed with the MBA process, paranoid, and even backstabbing.
When I meet other applicants, generally I just treat them as friends, and try to share useful info with them as much as possible or help with with the process. But i've met people who are super neurotic, creepy, and even annoying. Definitely fake/shady, like always kissing every student/alum/adcoms ass like no other, but when interacting with fellow applicants would provide fake info or not help at all.
These people spend thousands of dollars to visit schools not really to understand the school but to kiss the ass of everyone they meet, trying every backdoor way or shorcut to get into a school no matter what the cost or ethics.
Basically, just really desperate people with bad dose of inferiority complex, horrible interpersonal skills, trying way too hard to prove that they belong.
There are tons of nutcases out there applying to top bschools, unfortunatately.