It's a good point you make Tatters - the way I have always approached it is that Crosswords (most of the time) are ephemeral, here today and gone tomorrow. Granted some have large prizes but no link to a charitable fund raising effort.
Quizzes are usually over a month or some much longer than that to solve, in that time it is still on sale or available to download (depending on format) - if answers or heavy clues are given early on it has been proven that sales fall as it then becomes a simple lottery.
Re a list - well no, some sites do have unwritten/unspoken conventions on the topic and certain quiz setters do state 'no asking' on their sheets, not this one.
It's a hard call and I know I for one come over quite zealous on the topic. but I do love my quizzes.
I try to be polite in my objections as I am very fond of this site and the friends I've made here, though some names I only see when this quiz appears.
I think I've said enough, cue massive sigh of relief all round.