That's not a direct response to your concern, but I think this quote applies in a parallel manner -- I've seen this quote applied as a statement about what it means to be "punk", and how simply being content with yourself (meaning you don't fall victim to all the ways society attacks/preys on insecurities or tries to sell you drugs or makeup or clothes or surgery or whatever to change yourself), is actually incredibly "punk". You don't have to dress up weird, or go out and do graffiti, or get into fights... just being content with yourself is "punk", within a capitalist/post-capitalist world.
So, in a similar vein, I think this author is saying that, "caring" is also a form of being "punk", in a world where seemingly not-caring is mainstream now. The thing is, being "punk" doesn't need an external "why" reason to justify it... the whole point of "punk" culture is about authenticity, that just being yourself is what's important, that you don't need a special reason to reject capitalist consumerism or mainstream opiate-of-the-masses media or to dress how you feel instead of how society thinks you should look. In that way, being "punk" is quite Buddhism-aligned actually, to center on existence and enlightenment through self-realization, instead of pursuit of external "why" reasons for doing X or Y.
Caring is the punk thing to do, because it is who you actually are. You don't need a special reason to care, if you subscribe to any kind of "punk" mindset/philosophy about life. Don't care because it will yield better material rewards, get you laid, or whatever. Care, just because.
At least, that's the argument... up to you if you buy it or not.