You sound surprised that "they were cheerful, full of gratitude and positive". Me and my partner are also all of those things you mention as we realise (and they probably did 2) although we don't really have the money to "consume" needless goods, we have a roof over our head, and food and water in our belly. Which is alot more than most have in this world. As well as that we have (and probably they do 2) loving family and friends which again alot of people don't have.
So taking all that in to account why wouldn't we and possibly them be "cheerful, full of gratitude and positive". We are very lucky compared to, alot of people in the UK let alone the world (trust me when i say there are millions in the UK alot worse off than that little family).
Also of course there going to be full of gratitude not only did you give them a free bed but you also delivered it for free (good on you by the way
). They were probably over the moon when you left that house. IMO the less off appreciate thoughtful gestures more than the well off.This story just goes to show that needless gadgets etc aren't needed to be happy.
So anyway if that little family is anything like my little family (which they sound similar) then you have no need to feel too sad for them. They (we) are still the lucky ones..... for now anyway.