I really have to disagree with this attitude.
Suits are the great equalizer of clothing. They're designed to downplay the wearer's bodily proportions, and it's very hard to look bad in one. Most people can't tell the difference between a cheap suit, well-tailored, and an expensive one. The suit-and-tie pattern visually draws the eyes toward the wearer's face. Aside from these things, they have very little detail, and that's why they were the post-Depression standard businesswear in America, replacing things like morning coats and top hats and stripey pants.
Computer guys usually don't wear suits because they don't want to spend the extra time and money on them. That's fine. But it should be understood that the typical business casual getup is often visually more distracting than a suit, and does not emphasize the face over the body like a suit does.
You'd be better off just charging everyone $30 extra, and always wearing the suit.