This is just his blog. He's the chef of a framework, not an avowed HTML guru.
Have you seen the design for YCombinator.com? 1998 called and it wants its Arial font, <table> and <center> tags back. By your logic, YCombinator is worthless for helping Web startups launch.
Yes, but frameworks are supposed to solve issues like UTF8 encoding by setting up sane defaults automatically. If I wanted to deal with solved problems myself, I wouldn't be using a framework.
Also, YC's crappy HTML doesn't make the site less useful for visitors. This blog's poor unicode support does.
Have you seen the design for YCombinator.com? 1998 called and it wants its Arial font, <table> and <center> tags back. By your logic, YCombinator is worthless for helping Web startups launch.