Dave Rupert feels that Microsoft Edge switching to Chromium makes other browser rendering engines “edge cases”:
If there’s one thing I know about developers, it’s that we love to ignore edge cases because edge cases make our jobs more difficult. Google itself regularly ships Chrome-only products and I’ve been told by Googlers that they’re directed to only care about Chrome.
Like Dave, I feel torn between different arguments. But just as Blink is a fork of WebKit, who knows if we’ll also see a fork of Chromium led by Microsoft in the future.