At Boscastle, for example, there was no road access, people were trapped on the upper floors of buildings that were collapsing - a very different situation.
No, they were on the roof of a building that wasn't collapsing and would have been quite safe inside - the Fire and Rescue team led them to the roof. The only road issue was the bridge right in the middle of the village. To quote Max Boyce 'I know cos I was there'
Look at the Gloucester floods to see how many were rescued in situations that boats were wholly unsuitable for - fast flowing water inland is very dangerous.
However, it may be that in recent years, the emergency services have changed the way they approach flooding and personnel recovery, clearly they try to get people out earlier than they did.
A cynic might argue that if they are not tasked by the MCA (maintaining priority for the coastal areas) then it is no wonder we haven't seen any CG helos in the flooded areas.