As a developer, I can back this up. I made a web game that ran smoothly on an iPhone 4, averaging about 30fps, great on an iPhone 5 at 60fps, and like crap on the FOUR core Galaxy S3, at about 20fps.
Don't even get me started on the fact that I had to support Android all the way back to 2.3.3, and the Android Browser which has been modified by the various hardware makers (HTC, Samsung, etc) to break a few web standards we needed. I can't wait for the day when the whole world is on a late version of Chrome.
As a fellow developer, either you are exaggerating or you don't know how to optimize code.
And although fragmentation in Android is a real and big problem, you don't have to support Android all the way back to 2.3.3. You do it because you want to.