Security is a difficult topic, even for IT professionals, and it is easier to secure a locked down environment for non-technical users than an open one.
If you look at mobile platforms as an example, the prevalence of malware on Android compared to iOS is significant.
Now for many I'm sure that trade-off is worth it, but I also feel there is a place for more controlled environments.
But I'm under the impression that that is exceedingly rare and that Android has many way more pressing security concerns (e.g. the lack of driver security updates to even slightly old devices).
https://www.kaspersky.com/blog/android-root-faq/17135/
Also the control which allows users to install sofware from different sources, leads in many cases to them installing malware masquerading as "free games" or similar.
Android malware is a much larger problem than malware in the more controlled iOS world.
so to me that's a real trade off. you have control of your device and the ability to install software from more locations, however your security risks increase.
For some people that risk will be entirely justifiable, for others, it makes sense to have an option of a more locked down environment.
Personally I like Linux for servers (I have control/responsibility) but for my smartphone I use iOS as it's easier to secure and I don't really want to use that device for "proper" computing.
So clearly there's a significant demand (some of which I'm inclined to believe is very legitimate), and clearly there are significant dangers.
I guess in the end it comes down to the eternal debate of freedom vs safety. I find it very hard to side with the stance of protecting people from their own stupidity, beyond giving stern warnings. It feels sort of like giving up on cultural progress in humanity :/
And I think we could still do much more to mitigate this attack vector (Big flashy red lights with "probably a bad idea" in all-caps? Adding more fine-grained permissions so root is needed less?) before ceding yet more control to powerful organizations who are already, somehow, in a position to tax 30% of all software and IAP sales on most devices and reject apps that don't align with their interests.