Did you read the article? Those demos are not even part of html 5 yet (the ones that don't work on chrome and firefox at least). So calling them HTML 5 was not honest and a shameless promotion of Safari. Also, most of the demo do work great on both Chrome and Firefox, except the demos that are not HTML 5.
- Let's create some demos of our new HTML5 support!
- Do we want to be responsible for users' bad experience if other browser vendors make mistakes or implement things differently than we did?
- No.
That's it. Nothing nefarious about it.