That isn't a strong meta-point, it's like saying it isn't the bike, it's the cyclist. Sure Lance can beat me on a junker bike. But he can't win the Tour on a junker.
So if you want to succeed, and you have a choice about language, you still need to pick the best language for your circumstances. The importance of people and process doesn't invalidate that any more than the importance of Lance Armstrong invalidates the importance of bicycle engineering in the Tour.
All that being said, I agree with the last sentence of your comment. It's just that I don't meet many people who say that with the right language they don't need anything else, so I'm not sure who you're debating. For example, all of the Rubyists I know fetishizes testing. None of them have ever said to me that thanks to Ruby, they no longer need tests. What they actually say is that Ruby makes testing easier, which is your point.
So yes, process and people are important, we all agree. So who, exactly, says anything to the contrary?