That's a pretty ridiculous argument if you ask me.
Apple on the other hand offers a locked down product that many people want because they don’t trust themselves. I think a lot of people have short memories for all the hacking and spyware that plagued Windows users a couple decades ago. I think we also need to remember that Apple is not the government so people have alternatives to buying their devices.
Personally, I think people should have the right to buy a locked down device. It’s not on Apple to provide open competitors to their product. And why should developers have a right to develop for the platform? Heck, I wanted the iPhone back when it didn’t even have 3rd party apps at all.
The idea that, for many people purchasing an iPhone, the inability to install apps from alternative stores or the web is a selling point seems rather questionable.
On top of that this could easily be provided by an optional switch that enables you to enforce this on your own device if you so desire.
It is a poor reason to request that all app distribution for everyone else also has to go through Apple and its terms, basically for your convenience.
And that still plagues every computing platform now. Including Apple platforms. So the lockdown clearly didn’t completely solve that problem like a lot of people seem to claim