I think it's just the opposite. Also, schools and universites have switched from teaching most programming class in C++ to Java.

Java is indeed a lot easier to get into than is C++.
The larger core APIs are a main reason for that. No longer do you have to write tons of lowlevel stuff yourself (or find some often poorly documented 3rd party library which will likely work on only one compiler and OS which is always one you're not using) like you would with C++.
The documentation is also a LOT better.
Sadly this promise of a more easy start attracts a lot of people with no interest in learning at all, they just want a quick injection of knowledge to stuff their resumes.
These people disappear from the statistics as they fail to deliver but do increase the percentage of users dropping out.
With C++ these people never even try, and therefore the dropout percentage will be lower.

Java is a tough language to learn, but so is everything else. It's tuff because it takes so much persistance and time to learn. Not many people have the patience and "want to" to sit down, read, practice programming very small crap programs for years and years to get good. That is why most people drop it. They want to read 10 pages, sit down and write everything in office xp better than it is. The bottom line: programming takes time, persistance, a lot of work, a lot of help, and a lot of reading. You can't escape those, and if you think you can, quit now.