Yeeeeees...twooooo buttooooonnnsss...

Anyway, same happens with floppy drives: Amiga support two, but many software need all disk inserted in DF0, they weren't coded to read DF1 if you have it installed.
I agree some apps read joy buttons always as fire0, but internally there is fire1.

Remember, Amiga was for CODERS, not PROGRAMMERS. Methodology wasn't very appreciated... we needed every cpu slot for copper lists and bobs handling... forgetting to do it "academically"!!
LONG LIVE PAULA, GARY, DENISE.
LONG LIVE FATAGNUS