Free software is about freedom. Restricting it from anyone means it's not free. There is no requirement that we must create free software but if it's called free I think it should always have the basic qualities of freedom; not only when it fits our purposes and our values.
It's a choice for the authors to make based on what type of free they believe in. I think free under MIT and GPL are two different philosophies on how you see "free".
MIT: free for anyone, do whatever you want
GPL: free if you also make your software free
AGPL: GPL but SaaS can't circumvent the requirement to make your software free
I see why principled open source proponents would select GPL or AGPL. They don't just want their code to be used freely by others, they also believe more software should be free and using GPL helps with that.
GPL restrictions don't make software under the GPL not "free" as in freedom. Just a different philosophy.
And yet there are licenses restricting open source use. You should absolutely stop people from using your work if it doesn't align with your values.
> shift the default in open source from “it’s free for anyone to use” to “please don’t use this if you’re evil”
Point the author makes is precisely that they don't want to do free software, and they'd like to convince you not to do free software