I agree about the traditional blocks are worthless on the street. They don't protect you against an attacker with any kind of boxing skills. Street fighters aren't going to attack like a robot. You know.. step right, throw obverse punch.. leave it out 3 seconds...
This isn't to say that blocks that allow you to slip to the side or redirect force aren't useful. Hiki-uke for mid level punches can allow you slip to their hip and strike with elbows..or take him down.
Blocking a kick to your junk isn't as wise as just keeping distance. Gedan-uke in the traditional way is a good way to get a broken arm. It also leaves ones head unprotected. I could see using harai-uke if I was close and wanted to close distance even further.
This is all fine and well unless you run into a fighter with quick hands and footwork. Then.. look out!
keep training, Mark