Hurricanes are bigger. Hurricanes are stronger. Tornadoes happen more frequently. Hurricanes last longer. Actually, the list is pretty comprehensive.
Tornadoes are very short-lived.
To try and name them would be almost impossible. Think about the list of names we'd have to have. Hurricanes happen much less frequently and they last longer. Also, there may sometimes be two or more hurricanes happening at the same time. So, name recognition is important to let people know which storm the TV weather people are talking about.