I am no apologist for this charity but inter hospital paediatric transfers are well demonstrated to be necessary and to save lives. Both neonates and children need transfers to specialised units. We have national guidelines for standards and these transfers need specialised staff and equipment not available on HEMS
You are correct that that many hospitals do not have dedicated helipads some 30 years after it was made a national requirement to consider their provision, but this effects adult transfers as well and is not in itself a reason to deny these patients dedicated transfers.
There are not just helicopter transfer companies/charities available, there is a fixed wing capability in the UK within the private sector such as AirMed at Kiddlington who have undertaken many neo-natal and paediatric transfers and also CEGA undertake these operations. In fact Airmed undertake international neo-natal and paediatric repatriation work. A team two days ago brought a baby back from the USA, and in conjunction I believe with the RAF been to Bastion to bring a baby home and have moved patients from the North-west to the London area. Sometimes helicopter transfer is too slow for long distance transfers of paediatric and neo-natal patients.