Among many things, one thing I feel distinguishes the technical folks in programming and technology profession is its young age and not feeling the need of wearing suit. (Granted, there're young people in every workforce but there're relatively large amount of people in programming and technology field operating readily at high level professionally and technically at a young age.)

Similar to the sentiment expressed in Examine what is said, not who speaks." -- from BrowserUK's sig, in real life, it's not unusual for other people to judge someone by his look or age.

Once I was in a meeting with my boss, CEO, ~50, (both of us in street clothes) and our clients: a business unit manager, a technical personnel, and a newly hired assistant (~20) to that technical personnel (all in business attire, from industry where suits are norm). That new hire had an attitude throughout the meeting that irritated my boss, and yada, yada, at one point, that new hire bursted to my boss,

"If you want to be professional, why don't you wear suit?!"

Short silence followed by a fit of erupted emotion. The business unit manager promptly asked the guy to leave the meeting. (I felt like I was watching a movie.)

One day, my boss (not technie but smart) and a project manager (very technie, ~20) went to some technology convention. Whenever the two approached a booth, the sale rep always talked to my boss, presenting also all kind of technical stuff, and my boss pretended he knew what they're talking about. Pretty hilarious, actually.

I once interviewed a very very bright candidate who just graduated from college from another country. I asked a manager to interview her (in general I like to ask would-be employee to talk with his/her would-be coworkers). The manager (~40, former big name firm employee) refused to interview her, saying she's just a young college grad. He preferred someone more "experiened."

Since all other developers liked her, I hired her anyway, especially when she made the second brightest person in the development team (and I paired her with the brightest guy) and, funny enough, is much brighter than the manager who refused to interview her (which somehow reminded me of this post Re: Re: Homework threads aren't necessarily evil).

Consider the demographic info posted in Who am I? Who are you? Who are us?, where there seem to be plenty of competent Perl programmers don't even have college education (just like Shakespeare). For a capable person to be belittled based on trivial outward appearances is a sad thing. In formal axiological term, it's a systematic devaluation of a human being (intrinsic value).