I agree: I also work with Java and JVM languages and I was a fulltime Java dev for 10 years before but the first client (a bank) on our product insisted on .NET

I agree: I also work with Java and JVM languages and I was a fulltime Java dev for 10 years before but the first client (a bank) on our product insisted on .NET 7 years ago and we had some .NET expertise already and went all in. .NET Core is nice enough to do very large projects in though so I cannot see many reasons of moving away from it (especially from F# which I mostly use now).