The historical reason behind that is the > and | symbols were used as redirection operators to follow shell conventions so they used -gt and -bor. All of the o

The historical reason behind that is the > and | symbols were used as redirection operators to follow shell conventions so they used -gt and -bor. All of the other operators followed for consistency. There was also a big kerfuffle about statements like "$a = 1" or "$a++" not being able to return values like in C because if they were used stand-alone the return value would be printed out by the host.