[jcheng]

For several of Java's early use cases, being able to deploy a single file that could be run on any Java-supported platform was very important.

https://en.wikipedia.org/wiki/Write_once,_run_anywhere

[qznc]

Also, a small file and stack based bytecode is often the most compact representation.

[CalChris]

This is true and small memory sizes and limited bandwidth were design assumptions valid in 1992.