He doesn't say this directly, but I suppose his comment here:

"The whole 'do an all-nighter to get the paper in the day before the dealine' is something that should have gone out the window after highschool. Not for kernel development."

is making an explicit comparison to the behaviour of young adults (namely: poor time management, crunching for deadlines by staying up late). I agree with you that it's a poor editorialisation and makes it seem like Linus is being harsher than he really is in his writing.

Unrelated, but in general, a deadline can be used as a tool: avoid unnecessary work, focus. Especially, if it is a soft deadline. It is not just for teenagers, there are whole books on the topic e.g., "The Deadline Effect" by Christopher Cox.

There's the thing about how pulling an all-brighter to get something done before the deadline should have gone out the window after high school, which I guess is what's referred to? But this is just Thorvaldsen trying to encourage a healthy and sustainable process for himself and others, the title posted here is ridiculously editorialised click-bait.

He doesn't, but he does say that adults shouldn't be doing it, which can be interpreted as "grow up/act your age." I wouldn't really interrupt it that way, though.

>The whole "do an all-nighter to get the paper in the day before the [deadline]" is something that should have gone out the window after highschool. Not for kernel development.

>I wouldn't really interrupt it that way, though.

How so? I don't see any other interpretation

And while he might not use the exact words, it's a pretty accurate editorialized summary of what he says here

He's just explaining how kernel development is different from academics.

He did specify high school though, rather than college/university (or a generic like “school” or “academia”).

We’re probably all over-reading this quote but it did come off as a “grow up” comment in my reading as well, intended or not.

>is kinda mean and should be reserved for when people are being extremely immature. Linus didn't say that.

Isn't being kinda mean Linus trademark?

"Grow up" vs "leave it at high school" is "potato, potatoh" kind of difference...