So I've always substituted arrogance for hubris: the belief that you better understand, and can better address, the requirements than any off-the-shelf library/program/ecosystem.
He could have just used the word "pride" (which is far broader and has positive meanings too) instead. In some ways "ambition" might be a better fit.
In the context of "code that is going to be reviewed" maybe even "vanity" might have been closer to what he was getting at? (did you even RUN this?) Except us old neck beards obviously don't care about how WE look ;)} - just how our code reads.
I think "take pride in your work" would have substituted well; but given the options, maybe hubris was fine - he explains what he means in a couple of sentences.
Using a word and then redefining it seems very humpty dumpty "a word means what I want it to mean"
But you don't get big changes or ambitious intellectual growth without spotting that - if you did choose to break those sorts of rules - you could build something really new and exciting.
Anyhow that's how I've always taken the "hubris" part - knowing when there's an opportunity to achieve something in a way that someone will tell you is too risky.
I've always taken this sort of advice, such as "never reinvent the wheel" to mean "inventing the wheel is time consuming so give yourself an advantage by using already existing wheels", which really has nothing to do with hubris.
I never took it as "Don't bother trying to reinvent the wheel because you aren't capable of it"
If you want to build a car however, focus on building the car and not creating a new kind of wheel.
Look at the Apollo moon rovers, for instance: they couldn't use off-the-shelf wheels for those.
There's only one person I ever met who thought manual memory management was a good idea, and their code was terrible in lots of other ways besides that, so I can't say I've ever thought about that particular example.
But after a decade or so of "don't roll your own crypro", I've also heard that if you specifically want to get into cryptography, the only way to do it is to research existing crypro libraries and work your way upwards, starting from "can I find bugs someone else already found, without reading the full details of their report?" and eventually rolling your own.
[0] That said, I'd now also add that libraries serve as Schelling points to make it easier to find jobs and to find workers.
Part of the impact of jokes of this form is that you are supposed to be able to sort of reason your way there without explanation. But while laziness and impatience rely on the common usage of the terms, hubris is off in left field, and not even in a way that's commonly understood amongst software developers. Hubris is not "pride, but more so", it is specifically "unjustified pride". A lot of people first encounter the word "hubris" in high school literature/English class, talking about the common tropes of ancient Greek tragedies, where it is necessarily unjustified pride. I guess there's a way to understand "hubris" as "excessive (abrasively so) justified pride", but that seems vanishingly rare. I'd argue that that distinction makes "hubris" here misleading. When I (and, I expect, most people who learned the word in high school), read that a good programmer should have hubris, I understand that to mean a good programmer should be confidently wrong.