I can't comment in depth on the situation you're reporting, but it sounds bonkers.
In my bit of Hackney, just down our road, there's a public baths that opened in 1904. It was, in my experience, a good, basic swimming baths. In school holidays, it would organise events for local children – which seemed to have a good take up.
However, in 2000, the baths were closed. As it's a listed building, they haven't been demolished, but continue to just sit there. In 2009, there was some talk of a grant enabling it to be reopened, but it remains boarded up.
In the years since, the council has restored and reopened the London Fields Lido, which had itself been closed for some years. Unfortunately, that facility seems to operate on much more restrictive openings – specific age groups etc – so is nowhere near as easy to plan a visit to. I don't know what it does in holidays.
But since Haggerston Baths can't be demolished, it seems bonkers to me that it should simply be left to rot, with (presumably) basic work done on it to stop it being a danger. It's a facility that should have been kept open.
It's also been said that the local football pitches in the park behind us (floodlit, artificial surfaces) now command so much money to use that they are generally only rented by groups of adults rather than being used by youngsters. Youngsters do use the rest of the park, all year round, but it's yet another facility for more organised sport that has become tied to raking in money.
Now I'm light years from being a fan of Hackney Council, but obviously it is facing funding cuts and is pledging to not shut any libraries, for instance. But some of this seems very short-sighted to me.
Equally, I'd point out that there has been an ongoing policy of selling off school playing fields for 30-odd years that is also, I suggest, part of the general picture.