If you are a mobile software developer who refuses to deal with Android under the pretext it is "fragmented", you will simply be obliterated by your competition. The Android market is so large, and becoming larger every day, that other developers will gladly do the work you refuse to do. And they will succeed, just like the desktop/server software development world has learned how to cope with "fragmentation" in the Windows/Linux ecosystem by supporting the various OS versions, editions, service packs, distributions, locales, etc.
It does not matter what you think about Android fragmentation. It exists. Deal with it.
The point about the market being 'large' is the very thing that fragmentation undermines. What matters is how many paying customers can receive a good user experience from your app, and what this costs to provide.
You also assume that Android will continue to outpace iOS in terms of growth - i.e. the trajectory will be like the PC rather than like the iPod.
It matters very much what you think about Android fragmentation. Dealing with it has been a costly mistake for some developers, and could be for you.
It does not matter what you think about Android fragmentation. It exists. Deal with it.