#AndTakeAdobeFlashWithYou!!!
Java's 'write once run everywhere' promise only seems to work with malware. So many vendors want their own version and often break as even '.' releases change the architecture of the major release that did work.
Having multiple versions of Java installed usually leads to all kinds of compatibility issues as the Class registrations step all over each other. Often, the last version installed wins. The older exploitable versions can also be called and those exploits still exist on the system.
...at least this mess is job security.
...to those that think Macs are perfect...put down the Kool-Aid and slowly back away. As long as humans are involved, nothing is perfect. Not even a Glock.
As for whatever Linux distro is the favorite this month, the other 99% of computer users just want their software to work. They don't want to have to figure it out. They want to be able to go to Best Buy and buy a printer, connect it and go.