This assumes the ambitious are driven purely by explosive profit potential. Counterexamples are abound.

Why wouldn’t you? Nationalization does not imply profit is impossible.

Not to mention the purpose of the government is to serve its citizens, not just entrepreneurs.

Probably because raising money would be harder, would investors or venture firms weigh projects in industries likely to be nationalised lower? Probably.

Any industry likely to be nationalised would have an overall depressive effect on the number of risks taken on new products and services in that industry.

Yes, which is why I mentioned in my original comment that only services that are a “drain on the economy” should be nationalized.