Why doesn't anyone want a Junior ISA?

Only 72,000 JISAs have been opened since launch, despite being available to six million children in the UK.

According to sales figures from HMRC, only 72,000 Junior ISAs (or JISAs) were opened in the first five months since launch. This is despite there being six million eligible child applicants. Given that nearly half the adult population use an ISA, why does the junior version have such little support?