Of course you may wear usual boots. But riding boots provides more protection to your shins and ankles than any usual boots will do. Let me explain why.
1. Motorcycle boots are armoured. It means they come up higher and protecting your legs as well as your feet. What’s more, riding boots have a metal plate inside the sole to help prevent twisting. For what? If (hope this will not happen, but still) you will got into an accident, these special boots will both help you to remain on your bike and protect your legs from damage caused by the crash.
2. Riding boots were designed to have non-slip souls. Advantages are obvious. These souls will grip well – so they help you to stay on your motorbike.
3. Moreover, as a little bonus, bike boots are oil resistant. It makes them much easier to clean and keeps them looking newer for longer. These riding boots are pretty durable, so you won’t have to worry about having to replace them anytime soon.
Information taken from here.