I think most have mentioned the reason behind the 25 post requirement.
Just a note though, even though we don't have negative karma anymore, giving nuzzles over the most tiniest of things is not really how it should be either so learning why the function is there is really the better option.
Seen users in the past giving nuzzles to users just because they felt sorry for themselves when breaking the board rules, or just because the replied to a thread. Not really because what they had to bring for a discussion, nor because of good deeds. As much as spreading the luffles with the nuzzles can be good I don't see how nuzzling users over the tiniest of things but also telling users "I gave you a nuzzle
" I don't think it should work that way either, honestly feel like some would try to score cheap points and even getting a shot at getting a nuzzle back. And if the user themselves are new they might just exact do so.
This might not go for all forum users who like to mention they gave a nuzzle, but in many cases this is how it turns out to work.
The 25 post requirement is really a stable a good function to sort out so the Karma doesn't get abused in any way but still remain with some purpose and fun. This function has been modified several times since the site launch and this change I don't see any reason to remove.