I'd say that it's in a large part a question of marketing. SML and Haskell are largely academic languages, even if there is now Haskell running in production at

I'd say that it's in a large part a question of marketing. SML and Haskell are largely academic languages, even if there is now Haskell running in production at different locations. Likewise, you can hardly accuse OCaml of having the kind of marketing muscle and reach that a company like Mozilla can bring to bear (also, it's pretty old, which makes it difficult to sell as the new shiny).