Three cheers for our responsive mods.
I am doing another course, which shall not be named. In that course, the mods seem to be totally AWOL. Nobody answers the user questions unless a user tries to do it, which it appears might be the only answer the OP is ever going to get. Sentence/translation errors in the course go unfixed for months. That is evident by the dates when people post the problems and months later, nothing has been done. And not minor errors. Significant errors like a word being translated as a totally different and unrelated word. For example, what if I translated ship as apple. It was a big contrast for me to be seeing that in consideration of how on top of things the Klingon course mods are. We are lucky to have such a committed team on this course. I can guess they have sacrificed a lot of their personal lives for it. Thanks doesn't put food on the table but thanks to them anyway.
Edit: This is a bit fascinating to me. I have been informed on a post I made on the other language forum that the course I am taking there is not made by volunteer contributors but by Duolingo paid staff instead. Well, wow. I have to check out the other course somehow. If the volunteer course is better then I am going to just scrap the employee course, cuz it kind of sucks. I had always heard great things about the [language X] tree on Duo so I was really wondering what the sugar was going on. I was like, wow, THIS is the fantastic creme de la creme course on Duo? Pssssh.
One thing to keep in mind, however, is that courses tend to all have very active and responsive moderators when they are first launched, partly because the project is still fresh and partly because the number of users of the course is still small. With the passage of time, "life happens" with the moderators. They fall in love, have kids, get new jobs, get sick, have family crises to deal with, get involved with new projects, etc. Eventually, if the team is not refreshed, a course can be left with no support team at all (such as has happened with Italian and others).
I am sure our very dedicated moderators are not going anywhere anytime soon, but I think it is important for them to ensure that there is a continuity plan in place. It also helps, I believe, when non-moderator users (like us) do our part by answering simple questions in the forums for beginners.
Very true about the "project is still fresh, moderators are still fresh, number of users is still small".
Another course where I help out is the "German for English speakers" course which has been out for years -- and there, there are thousands of reports for every unit.
Many of them are of very low quality (obviously from non-native speakers of English trying to learn German and who don't know why "Did father is giving book to woman?" is a bad sentence -- that sort of thing), but that's still a lot of reports to sort through even if you end up dismissing most of them.
So the unfortunate reality is that you don't have someone going over every unit every week to see whether any new reports that are worth something have come in. And even good reports may languish for weeks or months or years because of the sheer volume of reports compared to sheer... non-volume of course volunteers and free time.
Plus there are more sentence discussions for German, and more active users = more questions. And lots of users on mobile = people who don't read the tips and notes, and ask the same question over and over and over again scattered over dozens of sentence discussions, wherever they happen to be when they wonder about a particular point of grammar.
So if the same people are answering questions on sentence discussions and looking at reports, then time spent on sentence discussions takes away from time spent looking at reports, and vice versa.
So if Klingon "goes big", then three contributors is probably not going to be enough, either -- especially since, as you say, "life happens" and three tends to become two and then one and then half of one who occasionally looks by, part-time.
On the other hand, just "hiring" a dozen contributors is not that great, either; the fewer people you have, the easier it is to keep a consistent "voice" or style in the course, whereas if you have lots and lots of people, you might end up with more inconsistency on what gets accepted and what not depending on who last touched a given sentence.
It's really tricky.
That said, as a user I'm glad for responsive course maintainers -- Welsh has been a breath of fresh air in this regard for me.