As additional protection against nefarious activity by malware or hackers, Apple has greatly tightened the requirements for authorizing installation of apps and moving of any folders or files beginning with Mavericks. Get used to it, those constraints will only become more stringent in the future. We all love to brag about our Mac's relative immunity to malware, but as has been noted before, "there aint no free lunch". Part of the cost of that lunch is the requirement to authenticate the change and/or movement of system files and applications.
Ought to be a way to target which threats the computer, given how it is used, is vulnerable to. Like, if you have a network firewall, do you still need all the additional lock-downs? If you don't use your computer at Starbucks, for example. I'm sure more sophisticated owners have modified those new features so they are still useful but less intrusive. Maybe options should be an option.
