Why do outlets burnout Should you just replace them?

Outlets burn out because the appliances plugged in are drawing too much current, thus overheating the contacts and eventually burn out. This can happen to any electrical connection when the amps or voltage required exceeds the capacity of the connector. In homes the fuses/circuit breakers will most likely blow/trip first.

Yes you should just replace the outlet, they should not cost much at your local hardware store, unless the outlet was a specific type. This can save you headaches in the long run with power stability etc etc.