The devices they are losing market share to do. (HTC is one)
I haven't seen any reports of them losing market share to HTC. What I have seen is a slow down in iPhone sales but that usually happens as word gets out that a new one should be released soon.
Don't forget:
And that was 1.5 years ago. Sure, some things have changed but hell, the EU said that phones should use Micro-USB and some phones are still sold with Mini-USB.