No it wouldn't. HTML 5 isn't completely adopted because it's not finished. Even Chrome, Firefox, Safari and (I think) Opera aren't completely HTML 5 ready because HTML 5 it self isn't completely done. Notice your browser likely won't get full points.
http://html5test.com/
IE10 actually scores higher then safari.
IE is the way it is for two reasons.
1)It was designed to kill all other browsers, and it did that at one point. To kill the others browser it needed to be core, and more stable, hence the long time between releases.
2)Trident engine based, closed source, and runs MSHTML.dll, it's MS's take on HTML of what they want. It's very likely that MS will not fully adopt every aspect of HTML 5. Same reason it didn't involve <Blink> tags. Not all browsers did. (this one needs citation, but IIRC that's the scope of it)
TL;DR IE isn't the scum of the Internet, they do what they do for a good reason.
I'm not here often, shoot a PM or whatever if you want my discord.