A necessary evil.
Originally posted on 9to5Mac:
Safari 7, introduced with OS X Mavericks, is now better protected against malware and poorly-written Flash code as Flash is finally sandboxed.
Sandboxing means that OS X restricts what the code can do, stopping a badly-written app from crashing the entire browser and preventing malware from getting access to any other part of your Mac. Flash has been sandboxed for some time in Chrome, Firefox and even Internet Explorer.