In 1995 when it was quoted in Hackers, and already 10 years old at the time, there were only about 40M people online worldwide. It was extremely uncommon to meet other people your age who understood anything about your "passion". That probably did lead a lot of us to get a little deep in our own head as we explored a new world while coming of age ourselves.
It was another time and understandable for it to be "cringey" for some who weren't exposed to it young and nostalgic for people who were. At the end of the day its probably best not to overthink it.
There was no Google, no Wikipedia, no YouTube. Today, the world largely runs on top of TCP/IP, and anyone can read some docs or any number of books and understand how it works. Back then, the world ran over the phone network, and there wasn't any way to really understand it except through phreaking groups and getting yourself into places you weren't supposed to be.
Before Linux, you'd hear about this wonderful, powerful OS called Unix. But you'd be tinkering around at home in MS-DOS unless you went to college or had a really progressive high school. The only way to experience Unix would be to hack or social engineer your way into getting access.
That doesn't justify the entitlement, no, or the ego. And it certainly didn't justify computer crimes. But this manifesto is from a very different age, where those smart kids were understandably frustrated because the world was yet to produce the tools and information we take for granted today.