Whether you intend it or not, it's an expression of condescension. It states that you are in a position where you can look down at (feel bad for) a lesser (poor Stallman).
You may not mean it that way, but it's exactly the same sort of phrase as "Bless your little heart".
If you "feel bad for poor him", you are referring to him in a way that implies his position is lesser.
"Poor $noun" is nearly always derogatory towards $noun. Off the top of my head, I can't think of a neutral or positive use for "poor $noun".
Verbal communication is imprecise enough that people will overlook "poor $noun". In text, you have the opportunity to proofread and revise your statements, so "poor $noun" drastically changes the meaning of the phrase.
Perhaps the condescension in my writing (of which there was none) was not so much in the signal as it was in the receiver? Your reply is absolutely dripping with it, window-dressing a cry of "is not / is so" with: "however", "furthermore", "therefore", and "by definition."
The only thing that would have made it worse would be putting it into pseudocode!