I think the point Max is that there is a segment who are only interested in a free bed, whether they could afford to pay for a hostel bed or not.
This is a segment of 'travellers' that gravitate towards anything they see they can take advantage of. Let me give a real life example. When I had my bar in Greece, two young guys came in one day and asked if there were any jobs available. I told them, 'sorry, no jobs here'.
They sat at the bar and told me a story of woe about how they had no money, nowhere to stay and hadn't eaten in 3 days. Now the funny thing is that this '3 days' comment seems to be a common phrase. I heard it numerous times from someone. It's an immediate Red Flag. You're dealing with a scammer.
These two guys continued to sit at the bar and try to extend their time. It was clear they were looking for a free beer. They didn't get one. Finally, they asked if they could leave their backpacks in my storeroom for a few hours while the went looking for a job. I agreed to let them do that.
A few hours later, they returned. Again, they sat at the bar, told me they didn't find any jobs, were going to have to sleep on the beach, yada, yada. Again they tried to prolong their time and obviously were hoping for a free beer or a handout of money to buy a meal. They got nothing. Finally, when about to go on their way, I went into the storeroom to pick up their packs and give them to them. As I picked one up, the top came open and out spilled half a dozen cans of beer.
How did they buy beer if they had no money for food? There story was all BS Max and they were not the only ones. This segment does exist and as I said, gravitate to anything they think they can USE without paying for.
No doubt there are plenty of people who see Couchsurfing, WWOOF, et al as ways to meet people, interract,etc. but there are others only interested in what they can get for nothing.