It's not so simple.
IBM dominated the mainframe computer market in the 1970s (by making a superior product to Burroughs, Honeywell, etc.). However, they required their customers to buy IBM disk drives, IBM terminals, IBM printers, etc. This was ruled anti-competitive by the courts, and it was made legal for competitors to reverse engineer IBM's interfaces, spoofing as needed, in order to make "plug compatible" peripherals (and mainframes). The public benefited from the competition.
Apple now dominates the music player market (by making a superior product to Archos, Sandisk, etc.). However, they want to tie the iTunes to the iPod-- this is anti-competitive. Palm is fully within it's rights to reverse engineer and spoof the interface in order to make a plug compatible peripheral -- and the public benefits.