HTML was designed for writing documents by people who are too stupid to realize that a proper GUI and a well documented format is vastly easier and more sensible to implement than all the shitscum that comes with parsing a horrible, textually-encoded standard as HTML is.
The web is far from designed to handle shit (and I do mean shit) like Discourse. It's like building a racecar (albeit a stupid waste of time and money) with a shoebox.
If you want to make a "website" -- as in, something based on W3C standards -- then make a website, not a fusion reactor to power your popcorn machine. -_-