Hating somebody for writing free software is not anywhere near reasonable. He never forced you to use it.

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.

The main problem was that a particular popular distribution made PulseAudio its default audio system before it was ready for that, and did a bad job integrating and testing it.

That wasn't Lennart's fault. PulseAudio is a really mature and stable system now.

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.

He aggressively promoted it and got downstream applications and distributions to adopt it, no?