Because if you dive into the archives, you'll find a bunch of grumpy people. Nowadays it's more relaxed, but still sometimes things get heated.
If you are sensitive to intonation of written text, like I am, one nasty comment can ruin your week. I've had/let that happen to me.
I don't have the mental fortitude to deal with that sometimes, especially from people that I respect and look up to, and the best for me in those situations is to stay away from the forum.
That's a me-problem though, and I don't want anyone to put on their silk gloves just for me. But it's a perfectly reasonable response for me to walk away from agitation and snarky comments.
I think we can all agree that hobbies are more fun if they're fun!
It can be quite scary to walk up to the big guys and tell them "Hey, I got this plant right here, what do you think?".
If they want to shit all over it, you can't stop them from doing so.
Except by not engaging at all..