[jll29]

For instance, the Java license explicitly forbids the use in/for real-time critical systems, and such limitations are good to stress in a license so that they may reach legal force, also to protect the author(s).

Incidentally, I've seen people violate the Java "no realtime" clause.

[jerven]

Used to, OpenJDK is licensened under GPLv2 with the classpath excemption that allows this for years. If not running an OpenJDK build it depends on your vendor license.

[goodpoint]

And it makes the license non-opensource.

Plus, the usual "no warranty" is strong enough to protect the authors anyways.