Thanks for the helpx link, looks like a good resource. For those with some skills, caretaker.org has quite a few opportunities for couples.
You bring up many issues common to WWOOFing and other "volunteer" opportunities. Often energetic persons like yourselves will give their heart and souls to a place in order to share in the idealism of the owners, but end up giving away a great deal, with the experience having cost them a great deal. Food and lodging is bare minimum for people's needs. You mentioned laundry as one essential. What if you get injured? How do you pay your car insurance (if you have a car)? Buy work clothes? Hosts often don't have suitable work clothing for workers. Transportation to and from places comes out of ones savings. Plus all the little supplies one needs. I've read a good many WWOOF host descriptions that require upwards of 30-35 hours for basic food and rustic accomodations! Though 20 hours is average it seems, which does not seem unreasonable. And many hosts offer paid hours above the minimum requisite, which is often necessary for the volunteer to make ends meet.
I think many hosts convince themselves that the "learning opportunity" is fair trade for the low compensation. I do not regard the "learning opportunity" of working on a farm to be in any way reasonable compensation. Every job is a learning experience. Everyone needs some amount of training in any new job. On a farm, typically the training is some brief instruction, minimal owner input, with 95% of the time actual labor. There are notable exceptions of course, but as many WWOOFers have experienced, many owners are only marginally capable themselves, don't have all that much to teach, and their need for technical assistance often far exceeds their own expertise. Trouble is, they often do not recognize it because they are not motivated learners themselves. Many hosts I've encountered avoid how-to books and would never attempt to research solutions by using Google. Most people greatly overestimate their own competence, and the degree to which they do is in direct proportion to their incompetence. This phenomenon has been discussed recently in psychology papers.
Yet I realize my conception of what is a viable enterprise and everything else, is often not the same reality as the landowner. And certainly every host has had to deal with lazy people or those who won't listen well or are a danger to themselves and others. But that's part of the risk of being an employer.
We tend to assume that because someone owns property and has some sort of enterprise started, and describes grand designs in their host description, that they have acumen, are organized, and actually have the wherewithall to succeed. So the WWOOFer needs to discern the difference between the hosts' reality and their own. While hosts are by and large fine caring people who need help, and volunteers are by nature and definition generous people who want to see an alternative farmer succeed, that dynamic opens the possibility of a landowner (or other alternative-type business enterprise) to take unfair, unintentional though it may be, advantage of willing helpers.
One aspect I've learned to assess as a good indication of a place I'd like to assist is their land stewardship. Land stewardship is actually rarely followed in any conscious way, and sadly the concept is largely unknown as to what it really means, even among some of those committed to permaculture and organic growing. If a landowner practices conscious land stewardship, their operation will be more organized and the land will not be used as a dumping ground for all kinds of junk. In fact, their land will not be "used" so much as "borrowed" from future generations. A primary focus will be made into increasing its biodiversity instead of mining its life and fertility. Yes sounds like basic permaculture and organic principles.
Maybe what "volunteers" need to do before committing to anything long-term is more up-front questioning. Perhaps do a 1-2 day pre-visit prior to a committment. It is hard to discern much via email or even phone. I also think it ought to be acceptible for experienced and/or proven laborers with good references to negotiate for their essentials besides food and shelter so that they don't have to bleed their own savings accounts while giving a part of their lives to someone else's enterprise. Right here on this discussion board, there are recent requests for "volunteers" for 25 hours a week and more in remote locations--for some fairly skilled work! And offering only room and board!