I don't see why the number of threads in the QZ is a problem. A nuisance, maybe, but a serious problem? How many seconds does it take to click on the section title and see the whole page?
You have to do that in the other sections anyway, don't you? 'English gesucht' moves far faster, and has many more threads that may not interest you personally, but you can still find what you're looking for there. I just don't see how the mere one line of the Zählfaden ---- or the six or eight or ten lines of the Frustfaden, Strandbar, QZ, CC, etc. -- okay, -- could prevent anyone from finding any other thread in that section.
I do see that the registration requirement could be a factor. I have the feeling that that may be the real issue.
Maybe it's also partly about just the unwritten expectations in the whole forum, not only the written guidelines. Sometimes the line between L&L & the QZ is not absolute, it's more a matter of thinking ahead and consideration for other people.
If you think that a discussion is in some sense relevant to language, that many people will be interested, that people may still want to read the thread months later in the archive, and that the topic will not automatically make people angry or emotional, then L&L is probably okay.
But if it's too off-topic, or too specialized, or too controversial, or not really worth saving in the archive, then the polite thing to do is to go to the chat room. Never fear, people will still find it if they have something to say.
And if Doris for any reason wants to delete, close, or move any thread, that's her privilege. I don't always agree with her -- I found the 'Schlampengesetz' title and many of the opinions in it offensive, but the discussion itself stayed relatively civilized (if largely one-sided), so I wouldn't have closed it. But it's not up to me.
Besides, I have the feeling she doesn't have time to sit around and weigh the pros and cons of every thread at length, so it's not a scientific decision, just a gut reaction. It's also not that big a deal -- this isn't life or death, it's just an internet forum.
We can make it easier for her just by erring on the side of cooperation. When in doubt, be helpful, not provocative, and I bet she will be more than happy to leave the thread alone.
And I don't see any age discrimination here, only discrimination on the basis of consideration for other people. If you stop to think before you post, and try to be as helpful as possible, no one will care how old you are. (-: