[groby_b]

There's nothing wrong with "That's a really bad idea, and here's why". There's everything wrong with "THAT IDEA IS FUCKING STUPID. YOU'RE SUCH AN IDIOT".

Do you really think the only way to communicate a mistake is like this: https://lkml.org/lkml/2012/12/23/75 ?

And Linus is perfectly capable of giving a more reasoned response while still being direct: https://lkml.org/lkml/2012/12/23/99 (same thread, Linus' reply to a reasoned response from yelled at developer)

Still pretty direct, but gone are the insults. Nobody has been asking for a sugar coating, but simply for Linus to stop being personally abusive.

Yes, people make mistakes. Really stupid mistakes. But if you think they're idiots, don't accept their contributions. If you don't think they're idiots, why call them that just because you can't control your anger?

[Karn]

And here we see the pitfalls of fuzzy thinking. There is all the difference between "that's a stupid idea" and "you're an idiot."