To sum up what others have said (and work my post count)

by people posting the:
"Hey I went to <insert place of complete randomness> in my kilt and <insert person of interest> told me <insert complimentary phrase>."

they are trying to remove any insecurities they might have by having otherwise random strangers give positive reinforcement to continue the behavior. This happens on other boards from all ranges of topics almost all the time. As this forum grows with its membership the frequency has increased because there are simply more new kilt wearers needing reassurance.

(maybe I did learn something from my behavioral psychology course in college)