But they are consuming benefits, presumably they are getting child benefit for all those under 18 and not working.
On a personal level, it is good to see such a large happy functioning family. My father was one of 11 and my MiL one of 13 and as a child I remember big family gatherings with all my aunts, uncles and their spouses and having so many cousins and family whereever I went in the country. Something my children have missed out on because DH is an only child and neither of my sisters had children, they have got the last remnants of the bigger family, but mainly at funerals.
On a wider scale however I think with the rapid growth of world population and the pressures it is clearly putting on the environment makes having such a large family is a very selfish act.