Everyone should read the guidelines really.

>If your account is less than a year old, please don't submit comments saying that HN is turning into Reddit. It's a common semi-noob illusion, as old as the hills.

I am on HN since many years, a user just recently. I was not implying that HN turns in to Reddit. I was implying that this comment is worthy Reddit, not HackerNews - a professional website that strives to hold on to some standards.

I have read the guidelines. Really.

There doesn't seem anything in the guidelines saying you shouldn't make jokes. Or it being a professional website for that matter.

This is true. However, while jokes are not expressly against the rules, the community moderation rarely favors them. Personally, I read a lot of Slashdot, and to some degree enjoy the level of humor, political debate, and anonymous commentary there. I find that the signal to noise ratio here is somewhat better. I don't think it likely that anyone would be banned for exclusively making joke comments, but generally I think the expectation is that while informative or insightful commentary may also be humorous, the primary purpose here is not entertainment.