The fact that iOS and Android are the only smartphone OSes did force you to do that.
Unless you mean that you could have made a competitor, but that's inane -- that's a completely different market, with huge barrier to entry.
Apple is using its huge market position in one area (smartphone OSes) to give itself a huge advantage in another (music apps). That's the sort of thing companies have got huge fines for in the past, or were broken in parts for.