Couple of thoughts:
Society had always had to figure out what to do with children whose parents can't or won't care for them. We are all part of Society - we are largely untroubled by these children unless they directly impact us or die and make the papers.
People at my daughters' schools knew they were adopted- did they help me? No, quite the opposite in many cases. I used to think to myself "I bet you would be rubbishing the sws if their birth mother had actually killed them" but that's as far as it goes. Same here - blame the social workers. But how many adopted children do you know and do you help or do you tut at their behaviour and make sure your child has nothing to do with them?
Adopters are currently being used to plug a completely underfunded service. Mostly people with no experience of challenging behaviour.
Imo the big problem is that the gov believes that anyone can adopt. If you have a spare room and no obvious skeletons or worrying medical conditions or extreme views, the chances are you will get through the approval process. It is a very low bar, with minimal training.
And this where I think the issue of it being right for gay adopters comes in, because they are corresponding as a prime group to be targeted. The council for voluntary adoption agencies says that anout a third of their clients ie people being approved to adopt are LGBT+. That is a huge figure! It shows how wide the net has been cast and how it is not so surprising that Preston went to gay adopters.
I think the problem is assuming that anyone can adopt and making the approval process so quick and then not funding post adoption support.