I can see that square heads could be torqued tighter than socket/allen heads, but why not just use a hex head?
The question is prompted by my having to remove a square head screw from the hub of a spoked wheel. What a bitch! There was no room to swing an open end wrench and I have no square or 8 point sockets. A hex head would have been a piece of cake. You can be sure that a hex head will go back in there, but why wasn't one used in the first place?
Bob