This is a commercial product - users expect support when things don’t work. You can’t simply reply with “Hey, go figure it out” and point them at a lemmy community.
In fact they address this further down:
but a lot of Linux users will see “We support xxxx” and they’ll go off and try a different distro. It’ll mostly work, but then something doesn’t, and it takes a while for us to figure out why, and then we get a lot of arguments over why their chosen distro should work, and why we should be supporting it.