Provides a nice contrarian perspective. Though I personally don't function like that, I can understand workers who work to enable other more important things (family, hobbies, etc). In essence, they trade being caged for stability, safety, personal time, etc. To some, that can be happiness too.
I don't think it takes anything away from PG's original point that for a lot of younger, more ambitious folks, being caged is not the best way to live or work.
Well in some sense perhaps .. you can also say working your ass off is like becoming "caged in work". The question really is what is more important to YOU. If doing excellent technical work or making money is your first priority, then if you are working in a megacorp, then one can say you are caged. On the other hand, spending time with your family or watching movies or travelling are important to you, startup life is a cage for you and you will feel "trapped" by work.
I don't think it takes anything away from PG's original point that for a lot of younger, more ambitious folks, being caged is not the best way to live or work.