One of the reasons that some people choose Java is that "It's a lot easier to find a Java programmer than it is to find a LotusScript programmer." Well, I think we all know the fallacy here, but I'll say it anyhow: if you find a LotusScript programmer, s/he knows Lotus; but if you find a Java programmer, odds are s/he doesn't. Unfortunately, decisions aren't always made rationally.
The truth is that LotusScript is an adequate language for most tasks, and it's safer than Java even in the hands of the most talented Java developers. But Java offers access to a far richer set of classes, tools, and generic talent than LotusScript ever did or can ever hope to. For any project that has a lot of tentacles and is expected to have a very long life, finding resources from the small subset of Java programmers who do know Lotus is the best approach.