Well yeah it’s hard to argue as I am also firmly against the inclusion of Nextcloud generally. And I think self hosting probably too. It requires too much knowledge for the average Joe.
What you really do not want is that people start putting these things on public cloud and believe they are doing something good for their privacy which isn’t the case. (Because of lacking e2ee). I have seen multiple times here on the forum but also on matrix that people do this because of the recommendations. But you also do not want people to open up their consumer home routers to the internet with DMZ or port forwarding. That just is a terrible idea.
When you would do all of these above correctly I still would vote against Nextcloud because of it’s stability. There have been a fair share of data syncing issues of which quite many are still open issues. Let alone even the shitty or no existing integrations of cal and carddav.