Hm that's not exactly correct. SEO is important, syntax / text interpretation is important. 100 DIVs helps nobody, but if you structure your page with article, sections ... bots, scripts and all technical stuff can interpret it.

Than, if you use sections, you can use header element and your text structure is more clear than in (X)HTML :-)

Its the same as in 2000`s, everybody use table as design elements. But table are not developed for design, it is for structured data.

I do not want to say that the tutorial is bad. for beginners it is a good start! But it becomes even more confusing for beginners when someone comes and say "use real HTML5 ... connect to the Share API" "what abput canvas" :-) ... I hope I could explain it well what i want to say