Ask HN: why shouldn't browsers come embedded with font-awesome like icons?

I have been thinking why should not browsers give some icons which can be used just like we use css styling properties. may be like, .somediv{ font-icon:"icon-facebook"; } It would be just too good for developers not to worry during development. We can avoid loading extra scripts and stylesheets just for this. Just a thought and would like to hear comments on this.