Psychology and image are tricky things.

For someone who ever represented his school, town, or country for sports or any other kind of event, wearing a uniform same with his teammates does give someone a strong sense of pride and belonging. It's probably the similar feeling for some people who dress up for work.

At the same time, for an exceptionally talented person to feel being judged the same or lesser than an ignorant snob in pretty clothing is an abhorring feeling.

Many skilled and creative people simply have too much of a personality and individuality to just follow suit (pun?).

As a matter of practicality though, for a single guy (common profile for many tech workers) sometimes only getting to sleep one or two hours a day or not at all, ironing his shirt and tying his tie would be the last thing to cross his mind in the morning (or ever).