Worth specifying here you're talking about VC-infested SaaS, not just your run-of-the-mill bootstrapped SaaS. It's very much possible to run a SaaS in Europe and make money, as countless of people already do, which I'm sure you too are aware of, but probably way harder to raise similar amount of money as US companies, that I'd agree with.

Edit: Strange typo; s/infested/invested, but kind of makes sense like that too so I'll just leave it, Freudian slip or something.