There's a certain amount of irony in startup founders who claim they relish the challenge of starting their own business and then turn around and complain about how challenging it is. Is it supposed to be hard or isn't it?
If startup founders were just looking for anything that could be called a challenge, they could poke their own eyes out and go mountain climbing.
Water, water everywhere but not a drop to drink. It boils down to no one will give the founders money.
Lots of talk about a startup hub location needs people, schools, devs, entrepreneurs, out of control rents, coffee shops or whatever, but if you copy everything about SV other than the VCs, don't get too surprised there are no VCs there.
The problem isn't him, it's London. If it's so unhelpful to good founders that they feel a need to pack up and leave, then London has a cultural problem.