I think many of us are in companies that are still very much led in the classic command-and-control style. Top heavy management layers, program management, project management, task management, a multitude of roles and processes.
All of this is created on the assumption that employees are dumb, lazy slackers that need to be told precisely what to do when, in a standardized way. Some say such organizations attract people with limited innovative capabilities, you could also argue that such organizations create people that way.
Some organizations even dare to constrain "innovation" in such rigid processes. Sure, feel free to come up with awesome ideas from the bottom. All you have to do is swim upstream, find sponsors, submit a business case analysis, etc. It's discouraging, more a process for anti-innovation.
The 20% time, when done properly, lets go of that rigid structure, and all the successes it has delivered are great proof that people want to make great contributions when given the freedom and trust. Sure, a minority will misuse the time just like a minority misuses working from home, but the general improvement for society is more important.
I have implemented my own 20% time, unfortunately self-funded as my company does not have it. Still, it sky rocketed my personal development, balanced my work and private life, and allowed me to build a cool website that is the marriage of two of my hobbies. I won't abuse this blog by plugging it. I will even take things further to opt for all of society to aim for a 4 day work week.