Yes, seriously. Stallman holds that it's immoral and unacceptable (in the world he would create) to have non-Free software. There are no exceptions.

Stallman desires to take away my choice to create (and implicitly, to use) software that doesn't meet his ideological vision of "Free" software. I reject that desire in toto; I do not presume to tell other developers of software what restrictions they may place upon software they right, just as I reject their attempts to do the same to me.

(Stallman's inability to fulfill his desire does not exculpate him from the moral failure of that desire.)