No, they hate flatpak, one of the many option to distribute software, which is not the only one even if you consider the “must run on many distro” restriction (which isn’t 100% true, kinda like the Java write once run anywhere). There are other options, some more involved, some simpler, to do so.

They didn’t say they hate devs, that’s on you, grabbing a febble occasion to tell someone that voiced his opinion to “fuck off”.