First of all, learning other programming languages is always a good thing. There are many reasons for this:
- Learning new languages makes it easier for you to learn other new languages in the future - and sooner or later in your career you will almost certainly want to or need to.
- Learning new languages teaches you different ways to think about code. And this can only make you a better coder.
- Learning new languages increases your employment opportunities.
- Learning new languages is fun!
In addition to these, and other benefits I've surely omitted, there's this which is directly relevant to your question about machine learning in particular.