That's true only if by "apps" you mean web only. Java is not the most popular language/technology to turn to unless you are facing amazingly large scale or performance is critical.

For startups developing in Java is probably not a great idea, because startups need to respond to change fast and get things up and running fast, and languages like Python, Ruby, some kind of LISP are way better at that. You can always re-write your application in Java/Scala if performance/scale becomes an issue (a lot of startups dream about having those kinds of problems :D).