Not really. It's actually kind of funny that a .NET programmer said that because Java and C# occupy many of the same niches, which is to say, heavy enterprise-y apps. But then that may be his point, that it would be redundant for him to learn a language so similar.

Java isn't a bad decision but I 100% believe you should try as many languages as possible, especially from different paradigms. Every language has something to like and most have something you can bring back to your primary language to be more productive.

Happy trails!

Java is currently unfashionable, and is popularly associated with enterprise architecture astronauts who add too many layers of abstraction to everything.

It's about as good as any other language, and has more libraries than most. It's also mildly annoying to work with, but so is any language when used as more than a toy.

You can do the same kind of project and get the same kind of job with .Net or Java. It really doesn't add much to your toolbox, although picking up one after you know the other doesn't take much time.

It's not necessarily a bad decision. Many people would say it's a practical one. However, it limits your thoughts about programming to one very narrow style, and not a particularly good one. There are many other styles of programming that are worth learning (functional being likely the most notable of them), and that will make you a better programmer regardless of what language you end up writing in day-to-day.

It's not a "bad" decision if you focus on Android development or you are working for a big company with Java infrastructure (that pay's my bills :). How ever, as they say: "don't keep all your eggs in just one basket". Learn other languages and frameworks like PHP/Yii, Python/Django or Ruby/Ruby On Rails. And code for different platforms (iOS, Windows Phone) if you have the time ;)

there is absolutely nothing wrong with java. I just rather spend my time focusing on the technology I like more and I want to work with.