I haven't used Spring, but I had high hopes for ASP.Net (C# is a very well designed language) and found that not only was the ecosystem around it decidedly lacking, and even the core libraries like EntityFramework were much less flexible and well designed than I am used to in the PHP/JavaScript ecosystems. And they didn't seem be that actively maintained either.

PHP usually has a good library for most things. JavaScript usually has 3-5 good choices (but nothing rails-like). .NET often seemed to have nothing, or only proprietary options.