I found this kevlar motorcycle jacket that looks like a casual plaid shirt. Why don't they make more motorcycle gear that look like this?
It's called the Axe 2 Kevlar shirt. The outer fabric is a synthetic blend, and it's just there for looks. Underneath that it a layer of Aramid Kevlar for abrasion protection, and underneath that there is a thin lining for comfort. There are pockets at the elboys, shoulders, and back to insert your own armor, which is not included with the jacket.
So one of the drawbacks is the price. It goes for about $500, which isn't cheap as far as motorcycle jackets go. And remember that you have to buy some of your armor separately.