Thing is, in the ‘olden days’, the only thing you could do with a home computer was tinker - the job of a computer was to be a computer but little else. And the number of people interested in doing that was small. Today, the job of a computer is everything. Computers are in everything and do everything. They are our interface to the world. Their value is what they enable - writing, tax returns, video consumption, gam…
Imagine being able to quickly and easily add your own custom programs to your iPhone without asking anyone's permission though? Also, what if - as the owner of that device - you had full control over it's capabilities like you do with a desktop computer? Adding these abilities certainly would not be the downfall of phone ecosystems as we know them. People that want convenience wouldn't leave their app store.
The fact that they are our interface to the world is exactly the reason why we need to take control of them away from the Apple/Google oligarchy. People need to stop comparing these devices to gaming consoles, which don't impact the world even a fraction as much as smartphones, when we're talking about making new rules for running smartphone platforms.