Only mentioned in passing, but I think the lack of offline installer will hurt open source users.
Open Source users get their Qt version from a Linux package manager.
This looks like a rather general remark to me, not specifically related to Qt. I don't think your argument is valid for Qt. Or do you have any representative evidence? Do you actually use Qt in your own projects at all?
The lack of an offline installer (i.e. a standalone installer that can be archived) is a bigger issue in my opinion.