It goes back to the days where DEC, NCR, IBM etc... came with entire portfolios of competing implementations, none of which interoperated with each other. IBM for example also had the "Insurmountable Platform Advantage", it had the full stack ... literally, from sillion, chip design, operating-systems all the way up to software-services, but the industry lost out due to big blue's big-iron prices and the pc clone-wars began.
I don't see what the pc clone-wars are in this case, android doesn't seem to make much of dent in apple's profits here.