From all of those cities Amsterdam and Tel Aviv a lot more innovative and the number of entrepreneurs was high (at least felt like it)
I think that there are few criterions that a city need to have to become a tech hub
- Relatively small city - Society who worship startups and entrepreneurs - Many Programmers and engineers (In Israel every 4 months few hundred talented programmers are releasing from the top units in the Israel Defence Forces, bringing high quality manpower to the ecosystem)
There are probably more criterions, those are just few I thought about now