I don’t think they are cynical- but after three or five or 15 years reading applications, they know a thing or two. There are a few fields where a young person can indeed be self-taught and achieve something significant in a few months, but most human endeavors require time, sweat, effort, a lot of failing, before getting anywhere.
A musical prodigy? That’s a kid who at age 12 has the technique of a 30 year old. But that kid likely started at age 3, has practiced hours per day, to become a “prodigy”. Kid didn’t just fall out of bed and decide to take up the cello and before you know it was playing at Carnegie Hall.
Not cynical- they just know a thing or two.