As a wwoofer travelling New Zealand, I am living with many different families and calling their house my home for the duration I am staying. Many are encouraging this attitude. Just like Couchsurfing hosts who let strangers crash on their couch for free, farmers and families tend to choose wwoofers overpaid workers not because they are cheaper, but because wwoofing is an opportunity for real friendship and cultural exchange. Unfortunately, some don't share this motivation. Part of the problem is that families can become dependent on wwoofers' help; those who don't have a grip on some aspect of their life will only become less disciplined when assisted. In that case, they continue hosting, even if they have trouble affording additional food, or spending time with their guests, which wouldn't be a dealbreaker for me. I a happy to offer my help and to give sincere advice.
I cannot deal with individuals who are not ready to face their problems, be it of habit, thought or circumstance. Those will always build walls to separate their issues from well-meaning others, often under the guise of customs and manner. Manners should help people feel comfortable, but when you call my behaviour inappropriate only because I am a guest, I get the feeling that there is something wrong with you. This example has aggravated me again and again! It is mostly not about specific rules, just a feeling that it is for me to justify everything I do in their house. Apparently, many see their property not only as valuable but as so sacred that my laying on their couch could spoil it forever, just because I am a guest. Now, I inquire beforehand if a host is willing to have us not only as guests but to accept us as friends or even family while we are there.
Please consider accepting a stranger in your home (they won't kill you), and let's try to be open to anyone. Not just open to formal exchanges, but to meaningful conversations, life-changing encounters, and ideas different from your own. I thought everyone was looking to make friends anyway.