[DanL]

I think at most, it was a stylistic thing. The main reason for my guess is because gradiants don't print well. The majority of promotional items - t-shirts, business cards, coffee mugs, etc. - they have writing on them through a process called silk screening. Essentially it means they develop a template and burn ink onto the object from that template. Take a look at some of your t-shirts - if they aren't the cheap iron-on type, you'll see that all logos are only a few colors - two, three, or four. The general rule of thumb is that corporate logos should be able to be recognized in as few colors as possible. It's near impossible to have an even gradient using silk screening. That and low-color logos just look better.