1) He didn't say "implementing it" is simple. Just that the language (using it, getting started with it) is simple.

2) Vendors get a lot of benefits by NOT providing a standard implementation (lock-in, for one).

3) It's not like everybody runs around implementing every new standard that comes out. Vendors have their own timelines and priorities. Heck, we've waited how many years for CSS3 to be implemented? (and it's still missing full support...).