I guess because very often people do have the puzzle in front of them - as was clearly the case in the one you linked to. But you won't get any responses from people who don't, which limits your range a bit.
If it's a popular crossword they know that lots of other people will be doing the same crossword too. Therefore they don't need to put all clues. The one you've used as an example got all the answers needed without having to put a long-winded question.
I was responsible for getting Answerbank to state that people should put clues and number of letters etc at the top of the question box. Unfortunately some people ignore this and still get their answers. Slightly frustrating for the rest of us, as we have no idea what the baffling clue was......
People put the question and get their answers. It doesn't matter who gives the answers, does it?
They are specifically asking others who have already completed the same crossword. Isn't that more considerate;rather than expecting people to solve the clues especially for them.
The original question by Rollo implied that the people who just give name and number of crossword along with name and number of clue, were assuming that everyone had crossword infront of them. But they don't assume that. They are directing their question to people who have already solved that particular crossword.
I have done that before, it wasn't deliberately to deny people of pleasure.
I think contributors should put the crossword, daye, clue and what letters they've got. I often trawl through contributions - sure, in search of an elusive answer - but spot someone else's query and offer a solution. That's what this site is all about, isn't it? Giving something back if someone else has helped me!
A week later, it would be good if at least we had, for example, dtgk, and the date and the number of the clue.
As others, I trawl through all the recently answered questions, and always finish up with answers that I haven't already got.
Thank you, especially, to Jim Jools, virtually every week
However, still haven't finished dtgk 1-12-2007; 16a cold potage parmentier; 32a mud-like sealing layer; 54a song with alternating solo verses etc. and 42d quotation from Richard II