I would think you would try to perfect what you have instead of making new ones all the time.

Perfecting what you have often leads to a completely different language. See C vs C with classes which ended up being C++.

There is absolutely no problem with creating new languages. These are often designed with specific features in mind, and the success cases often offer features that are in high demand. Take for instance node.js, and how its event loop makes it a near ideal language for network-heavy applications that run on a single thread.