smoggle - it is actually difficult to staff - particularly morning club (that's one of my jobs as school admin, to recruit and staff these clubs) There are a couple of reasons for this -
its an hour a day before school, the person has to be trained to an adequate standard (safeguarding, first aid, childcare, food handling) but not be interested in working during school hours but be interested in working when their own child is probably being got ready for school. The obvious thing is to extend TA hours, but TAs are about supporting education and often good TAs have lots of skills and don't want to do childcare at that time of day as they have their own children.
The school's purpose is to educate children and so raising education standards always has to be the schools focus. Things like wraparound care can be a distraction from this focus. Ofsted, governors are looking at the quality of the education you provide. the government gives you money to educate children.
Its not as profitable as you think because of the costs and space needed and the knock on things like caretaker hours, cleaning contracts, when repairs can be carried out etc
There isn't the demand. I mean, obviously there is demand but its not as consistent as people think. Lots of people work condensed hours, granny drops off on a Thursday, their friend helps on a Monday, dad get the later train 2 days a week etc - so we find that we are oversubscribed midweek but cant fill the places on a Monday and Friday. Its the same in the holidays - everyone wants holiday care, but not all at the same time as they do have annual leave and fancy tennis club for the first week. We have more success only proving care one week of Easter rather than 2 as what happens is you get, say 30 children, spread 15 each week instead of all 30 in one week. But then that's difficult to staff as its not really a job is it - half the school holidays.
So in summary, I actually agree with you that decent childcare is possible because that's what we have going where I work - sort of - but I think the current set up with education makes childcare hard as schools aren't funded to provide childcare and it is a distraction from their purpose and the school day is the middle of the working day really. It must be possible but there needs to be a big shift in political will to actually structure education and childcare and look at funding.