That is arrant nonsense. I am an end user - free software is important to me not because I want to fiddle around with the source code today, but because I may well need to have access to the source tomorrow.
Yes I am a programmer, but that's a lot less relevant than you seem to think. I'm not an iOS or Android developer - I'm sure I could learn those skill if I needed to, but I can always hire someone to do it for me... and of course that option is available to any user of the software, not just programmers.
To imagine that software freedom is about programmers satisfying their curiosity, or fiddling with their phone's UI is to miss the point entirely. It's about control. It's about my ability to control the device that I've bought, and the software that I choose to use on it. It's about me being able to get a new feature that I really need. It's about nobody being able to take away software that I've come to depend upon for my livelihood.
The problem with Apple's $100 per year is not the money. The problem is Apple's ability to take away my freedom to modify my device as I see fit.