battery quick disconnect

Does anyone know the reason for those quick disconnect fittings being only 
designed for the neg /ground terminal? Obviously disconnecting either 
terminal would shut down the electrical system. For my positive ground Bugeye 
I would have to either put it on the "hot" neg terminal or grind out the 
fitting to get it on the pos terminal. Are there any scientific types out 
there that can come up with a reason one way or the other?      Just 
curious,-----Bob Chamberlain