Babies unwelcome at St Michaels Mount!

While we were on holiday we visited the National Trust Property at St Michaels Mount.
The guidebook has plenty of warnings about the slippery causeway and steep steps.
But with four adults to help deal with a three-year-old and 9 month old baby we managed easily.
Just before lunchtime we went to the Sail Loft Restaurant, the guide says "Menu features local seafood dishes Children's menu".
We ordered for the five of us and said "can you warm our baby food for us"
To our surprise the reply was we don't do that, leaving us no choice but to cancel our order and walk the 800yards back over the slippery cobbled causeway with a hungry baby.
David and Helen had paid for a yearly season ticket for the National Trust a few days before; I hope they get a better welcome at the other National Trust properties.
I have since checked with a Senior Heath Inspector and there is no legal reason for this unreasonable act.
It wouldn't be a problem to change restaurants on the mainland, but to do this on an island is unforgivable.