Read lmm's comment again. His dislike clearly arises from the problems this software has apparently caused him in the past.
I don't think it matters if the software in question is open source or closed source, or if it was obtained for free or paid for, or how the developer was compensated, or if it were developed by an individual or an organization, or why lmm had to use it in the first place.
Causing people unnecessary grief will invoke a negative reaction. That's perfectly understandable, and quite reasonable.
I disagree. PulseAudio is a prime example of Lennart confusing an issue that is fairly specific to Linux to an issue general to Unix. Other Unixes have solutions to the problem of a limited number of audio channels; in such places, PulseAudio only adds needless complexity. Had Lennart instead worked with the people of the Alsa project to improve it, we wouldn't have had any of the problems we saw with pulseaudio, and we wouldn't have yet another layer to deal with in handling audio.