So java and similar languages are better suited making games and web pages.
Good luck persuading thousands of multi-national businesses that the main language supporting their enterprise backbone is better suited for making games and web pages.
Java can do both those things, yes - and while I'd argue with creations such as JMonkey it's actually a rather good choice (technically speaking) for creating a game these days, I'd agree with celegorm that that's definitely not what it's best for.
Arguably Java's greatest strength (cross platform penetrability) is also it's greatest weakness - it can run on any platform, but because of that you can't make use of platform specific libraries and expect it to still run anywhere. Monitoring CPU temps and suchlike are the sort of tasks that do full into the category of applications best done in a native, architecture dependent language - you can do it in Java in a cross platform way, sort of (and indeed I have once just for the heck of it) but you make the task far harder for yourself than if you just wrote separate Windows, Linux and Mac versions.
For big apps that just use this as a small component, if you wanted to maintain the cross-platform advantage you would usually write these small parts in native code and write the rest of the app in Java, using JNI to link the two.