No... they weren't getting robbed they were just folk that were too dumb to realise the Amiga was the better machine and deserved to be ripped off... 
I don't think Joe Average bought a PC anyway in the 80s, rather just your 8bit Commodore, ZX Spectrum or MSX. IBM came from the business/server market and had the business know-how and software. Ergo, the business was screwed big time in the 80s yes.
Likewise the Mac, but then on the graphic department.