If only there was a way to make a standard where all the way things to be displayed on a users screen were expressed in a consistent way and all the things that display the content interpreted things in a consistent way then none of this would be necessary.
It all broke down though when someone decided, "Hey, I can do this better" which is why there has been such a convoluted journey to get to the HTML 5 standards.
Now all we need is for everyone to just adopt that and move on.
I agree with @jake (so have an upvote). Its my choice as to what I decide to browser on and which browser I'll use and if it doesn't work / works differently, well, give me a bug reporting form and I'll tell you and you can fix it.