They shouldn’t have to be, that’s the comfort zone of graphics designers.
Nobody is knocking the programming language here, the main beef is with the Java runtime and its unfriendliness towards end-users and its difficulty of deployment
I’ve been playing around myself a bit with bundling a runtime with an application (according to my wishes of making it as simple as running a native application); through some efforts I’ve actually managed to create a little configurable tool that can strip down a JRE in several ways; I’ve tested it on a Java 6 64 bits JRE and I could take it down from ~100mb to ~28mb, about 14mb when 7-zipped. Not bad!
The only problem with that is that I have to yank out far more than Oracle allows in the rules for runtime bundling, so its no good for commercial stuff
The biggest contributor to the size is not the binaries but the rt.jar; for game development purposes I strip out everything that you don’t need in a game which includes anything related to XML, JNDI, corba, JDBC, etc. etc. Hopefully, Java 8 with its modularized approach will make that easier to do and at the same time legal to distribute.