When you publish something under an open source license, you entitle the rest of the world to use it to get rich. That's what the license says on the tin, what the licenses have always been advertised, etc. I have absolutely no problem with AWS or WPEngine using that entitlement, nor do I have any problem with any software engineer (or software engineering organization like AWS) choosing not to publish source code they didn't promise to. Even if I wasn't of this opinion though - I don't see how someone violating this supposed prohibition could possibly entitle Matt to lie/cheat/extort/defame/...
Edit: I know it's off topic to talk about flagging, but can we consider not flagging the comment this is in reply to? I think it's generated valuable discussion for people learning about this case... even though I strongly disagree with the author.