I have found a shirt that fits me perfectly so I bought a couple more of these. As long as it's a good fit, you enjoy wearing it, people don't scratch their heads looking at you, why not wear the same thing all the time?

Of course not looking sloppy is important (hair, fingernails, showers, clean clothes, etc.), but other things are much much more important. Integrity, getting things done, an inspiring and/or knowledgable personality..

Also: I don't know why Steve Jobs has to mentioned in every second blog post on HN. Yes, he wore the same clothes all the time. But you don't need his permission to do so. You should be your own boss, and your own fashion consultant. (When in doubt, ask your wife or girlfriend though. ;))