It's not a "rip-off" - it's a derivative. "Patcher" was Miller Puckette's original (internal) name for Max, and there has been an open-source line of the family for 25 years in Pure Data. You can read the history by the man himself here: http://msp.ucsd.edu/Publications/dartmouth-reprint.dir/

Calling it a rip-off is like calling Guille a rip off of Scheme.