Legacy exists in every company and platform older than some years. You either do the business of brownfield jobs or not. Every platform has their ugly history .

Legacy exists in every company and platform older than some years. You either do the business of brownfield jobs or not. Every platform has their ugly history .. they just call them differently: SOAP/WS, RMI, CORBA, 2to3, PHP4, jQuery, AngularJS 1, ... . If a platform does not have history, I would be worried that I am riding something which soon is the legacy. Microsoft does not play catchup in the web space. It is in the pack for some years already. The stuff they do with Blazor is at the upper end of the pack. .NET, like Java, is not cool. It does not need to. It gets the job done without any experiments in a very modern platform. Doing a startup with boring tech is a thing. So in summary: .NET is a very good choice for a beginner or converts. It is fresh, you can do solid stuff, do the full stack in one platform (web, desktop, apps, games, iot, ML, ...) and there are plenty of jobs (greenfield or brownfield).