Many people in startups wear costumes too, just a different sort for a different purpose.
I realize that people in tech generally avoid "suits", but there is a time and place for dressing up and there are certain industries where you need to wear the uniform to play the game. Maybe it works to show up in flip flops as the founder of Facebook, but if you're trying to sell someone a mission critical product and they're going to spend tens of thousands of dollars...
...oh man, I digress, this thinking deserves a blog post of its own.
I don't mean anything by it, I just like tailored stuff. It looks good! It's highly evolved to maximise what men have got. But: if I wore one to most of my meetings, or to work, people'd ask questions or make a bunch of unfounded assumptions, so I don't.
It's a myth that technical communities don't care about clothes. They do - it's just they send a very particular set of signals and, what's more, they're the signals common to countercultures. That's fine: it's just another code, no more or less than any other. It'd be discourteous to go against it. I'm still going to be thinking wistfully of the ties in my wardrobe, though!
I bought a suit when I was in Syria two years ago and its probably the most comfortable piece of clothing I own.
Since then I have tried to be more aware of my assumptions and less swayed by appearances, but I haven't always succeeded. Heh, I recall another incident where I roundly ignored an attractive woman at an entrepreneurship meeting, only to find she was a CEO and one of the panel speakers.
The three-piece suit has become sort of my trademark. You don't see them much anymore. It has several benefits: You may be overdressed on some occasions, but you can manage to fit into a huge range of circumstances.
[OT: after having been to the trade show, I still don't know what CBOSS do, besides hire lots of models to man their stand...]