Why is Java so popular

The introductory programming course at uni teaches Java, but you don't have to take it if you know a programming language. Should I teach myself python over the summer (I already know the basics) and avoid having to learn Java? Or are the haters just people who are scared of object orientation.

OK i think I will do that -- learn python now and over the summer and next semester I'll learn java at uni. When I start java though is it a good idea to independantly teach myself another language at the same time or is it better to learn languages one at a time?