They did use someone else's work, though. If you recall, Philip Wadler (of Haskell fame) designed Go's generics.
> but by so doing end up with poor reinventions of well-studied concepts.
Which is funny as there is probably nobody on earth that would be more capable than Wadler to get the job done. His pedigree in that area of work is pretty astounding. If he couldn't do more than create a poor reinvention, what hope did the laymen working on the Go core team have?
Answer: They had no hope. It's not like they weren't trying. Ian Lance Taylor, for instance, is well known for beginning work on generics in Go before it was even first released to the public. He, among others, quite simply, were unable to figure it out.
Everything looks easy and straightforward when observed comfortably from an armchair, I suppose.
Stop excusing them, they were the first to acknolowdge being wrong in first place,
"They are likely the two most difficult parts of any design for parametric polymorphism. In retrospect, we were biased too much by experience with C++ without concepts and Java generics. We would have been well-served to spend more time with CLU and C++ concepts earlier."
-- https://go.googlesource.com/proposal/+/master/design/go2draf...
What is there to excuse? Your quote confirms that they simply don't know what they're doing as was already established. Not that anyone should expect them to. They're just regular average humans, same as every other random Joe you encounter while walking down the street, who all equally have their own failings and shortcomings. Why HN is constantly trying to put these particular people on a pedestal, I'll never know. Jealously that regular bumbling idiots just like them accidentally stumbled into creating something popular (for some definition of popular), perhaps?