Can I question the orthodoxy on this one?

Suppose WebKit or Blink are the one engine that everyone uses. Do you know how much uncertainty and effort that will save around the world that goes into browser compatibility and quirks? Look at the x86 architecture or POSIX as well.

Here is my serious practical question: this is open source, so if you want to make some extension, you should be able to distribute it. And if it becomes so popular as to be merged into the core, or included with the main distribution, then it will be.

It seems on balance, this would be a good thing.