The posts are there, but the nets almost never are. There might be several reasons: People steal them; there are less public pitches now than there used to be; there is simply less space in the UK than in the US; there are more teams in the UK, and so more uses of pitches, therefore more damage to nets, therefore more expensive to replace; it's an easy cut for UK councils to make; we are still subject to post-war rationing of football nets; we no longer have a fossil fuel industry to make the plastics for the twine. Take your pick. I have actually commented on this before driving round my town, as in the UK, Sunday teams would have to bring their own nets for every home game. Here, they seem to be in place. Are they simply less used in the US? Are they only found in more community-minded towns? Are Americans simply more community-minded? Does God protect the nets in the US? Who actually pays for them and puts them up here?
I feel that I have over-thought this.
Never any nets on basketball courts over here either and neebody plays that.