It does sound a bit weird. On the other hand, if he can influence the choices positively, he does have a point. If not him, someone else would take the job. I would have drawn the line somewhere else but I can understand where he is coming from.
And the fact that he resigned means that he has and likely had some moral compass guiding him.
There is also AppImage Launcher which works nicely for me. It automatically integrates AppImages into the DE (e.g. search and start menu) and a few other nice things.
https://github.com/TheAssassin/AppImageLauncher