Has it occurred to you that although it's being promoted from the angle of helping families, it's actually a deliberate boost to the economy?
Cut VAT on children's meals, restaurants get increased footfall and at least one adult eating as well, thus increasing the business income and making it more likely people will keep their jobs.
Cut VAT on attractions, cinema, theatre tickets, they get increased footfall and at least one adult plus the income from the children (and maybe a friend), thus increasing the business income and making it more likely people will keep their jobs.
Cut VAT on these things, people are more likely to use public transport (especially in the areas where children can now travel free), thus increasing business income and making it more likely that transport services will continue and more people will keep their jobs - particularly as it's for everybody, not just families in receipt of UC (not that it will stop the chronically resentful bitching about how UC is a life of luxury and they can't afford it without a discount - well now you're getting one, too - still unhappy? Of course).
It's a targeted approach to support businesses that are being hit precisely because they'd come under discretionary/optional expenses that people don't do when they are feeling the financial pinch.