https://www.gnu.org/philosophy/open-source-misses-the-point....

> A pure open source enthusiast, one that is not at all influenced by the ideals of free software, will say, “I am surprised you were able to make the program work so well without using our development model, but you did. How can I get a copy?” This attitude will reward schemes that take away our freedom, leading to its loss.

> The free software activist will say, “Your program is very attractive, but I value my freedom more. So I reject your program. I will get my work done some other way, and support a project to develop a free replacement.” If we value our freedom, we can act to maintain and defend it.

Relying on Slack, Github and what have you is clearly not to "get my work done some other way, and support a project to develop a free replacement.” It aligns with attitude exemplified by the "pure open source enthusiast".