Google has been bombarding Firefox users with "Upgrade to Chrome" notices on their properties. Google kept having "oopses" that blocked browsers based on User-Agent strings, rather than capabilities.
Google also plays "fire and motion" with Web standards. They have a tendency to use non-standard(-yet) features on their websites. This gives them a perfect excuse to make other browsers look technically inferior (when the features are missing or the browser is blocked) or slow (when the features are implemented using inefficient polyfills). The unfairness is the one-sided choice of using whatever cutting-edge or Google-specific feature Chrome has, while they'd never do this in other direction. If Firefox implemented a new feature first, Google would never tell Chrome users that Chrome sucks and they need to upgrade to Firefox.
Google also plays "fire and motion" with Web standards. They have a tendency to use non-standard(-yet) features on their websites. This gives them a perfect excuse to make other browsers look technically inferior (when the features are missing or the browser is blocked) or slow (when the features are implemented using inefficient polyfills). The unfairness is the one-sided choice of using whatever cutting-edge or Google-specific feature Chrome has, while they'd never do this in other direction. If Firefox implemented a new feature first, Google would never tell Chrome users that Chrome sucks and they need to upgrade to Firefox.