It means overdoing it. Saying please and thank you isn't unnecessary but doing it over and over in the same post and throwing in a few Sirs as well can be a bit over the top. There's a certain type of poster on this forum that displays that trait.
I do not support the constant repetition of the said words in the same post because over doing it will make the words loss its value.
And Yes, I agree. There are certain type of posters who might have that trait but the way Theymos exhibited it makes it looks like a bad thing.
Anyway, just thought I should say out my mind, no harms done anyway.
that unnecessarily polite is pertinent to short reply mostly at alternative cryptocurrencies board, which if allowed would turn the forum into spamming nightmare, but in general one should be more polite towards other as to not just shout profanity at others all the time in the discussion.
On the other hand that board actually have nothing more than just weekly report board for the bounty participant, you will learn nothing there.
This is also what I meant by it's constant repetition in the same post is what I don't support unlike people who say them out of genuine gratitude.