Sometimes having your own language just fits into the larger ecosystem better than any existing language. Several of the major languages in the last while were

Sometimes having your own language just fits into the larger ecosystem better than any existing language. Several of the major languages in the last while were about ecosystems more than the language. See C# which is basically Java, but for .NET. Once the decision not to use the Java standard library or VM was made, why try to adapt Java directly? Or see Swift, which meshes with the Apple ecosystem well. Language and compiler level support for reference counting that Apple likes these days. They could have used something like a strict subset of C++ with their own libraries. In fact, they did originally. But it was pretty kludgy as I understand it. And they were using their own compiler already. Might as well use your own language?