[osigurdson]

Monetizing software is so incredibly indirect. Obviously companies don't make any money on free frameworks and tooling. These days, using C#/.NET maybe/kinda/sorta increases the chances that you might deploy on Azure or use Azure services. That tiny (or not so tiny) uptick easily funds all C# / .NET ecosystem development.

I'm not sure why they do not open source the debugger. I suppose it is obvious to some extent that some companies (JetBrains) are able to charge for high quality tooling. Microsoft makes a trickle of money from Visual Studio professional.

Though the objective function and decision variables are somewhat opaque, this is clearly an optimization problem.