He specifically didn't say that. Instead of criticizing that they aren't nuanced enough you should read the nuance they actually wrote:

Let me be clear: The odds of a massive, immediate shift away from Windows PCs aren’t great. This isn’t a “year of the Linux desktop” rallying cry. But if there is a Linux desktop that exists today, it’s the Steam Deck. And that makes SteamOS a bellwether for greater proliferation of non-Windows devices (if not necessarily “Linux” specifically) in a huge range of form factors.

I don't know how long it'll take desktop Linux to reach 10% market share. Could be a couple of years, could be decades, could be never. But once it reaches 10%, I give it 5 years before it's over 80%.