Because some people like to exercise their sense of humour, without appreciating that it might not be required in all cases. I admit I've done it in the past - apologies to anyone i may have unwittingly annoyed.
Exactly Buttons.....This is a free service which people give of askig nothing in return.....If you managed to get an answer to a question that you were stuck on then what's the problem?
Because we all secretly think we are very funny and can have a ready made audience for our jokes out of other answerbankers when in real life our friends would tell us to shut up.