That's really not the question. Any language that we've all heard of is pretty much by definition a wild success, comparatively. Most languages stay very small.
There are very large first-mover advantages and network effects to programming languages. Programmers want to learn languages existing code is written in; companies want to use languages that lots of programmers already know. Languages that get big for historical reasons tend to stay that way.
Mainstream adoption wasn't the main goal for a lot of functional languages when they were created: the aim was to develop ideas of how programming could be better. The surprising thing, really, is that people write real production in some of these languages, despite how different they are from what most programmers already know. We shouldn't be treating not getting as big as Java as some sort of failure.
There are very large first-mover advantages and network effects to programming languages. Programmers want to learn languages existing code is written in; companies want to use languages that lots of programmers already know. Languages that get big for historical reasons tend to stay that way.
Mainstream adoption wasn't the main goal for a lot of functional languages when they were created: the aim was to develop ideas of how programming could be better. The surprising thing, really, is that people write real production in some of these languages, despite how different they are from what most programmers already know. We shouldn't be treating not getting as big as Java as some sort of failure.