> Asking for help is an exceptional event.

"Exceptional event" is not a useful or well defined concept. A better concept is "error" or "unexpected result".

Asking for help is a request for information. The normal, non-error, expected result is that a bunch of text will show up on the output. It is entirely reasonable that the "next command in the pipe" might want to do something with that expected output.

I shouldn't have to guess whether or not you think the output I specifically requested is "exceptional", so it's entirely reasonable to expect that programs in general consistently put user-requested help on stdout.

You are of course free to write your software any way you want. And I'm free to think it's stupid, and to not use your software.