Почему я должен заботиться о статистике Ядра NTP?

NTP is a protocol that synchronizes the system clock (usually there is a daemon running on *nix boxes). In short, it makes sure that the time on the server is correct. There are many reasons it is important to have accurate time:

• Some authentication schemes (such as kerberos, AD auth) count on the system having correct time
• When you troubleshoot things, having accurate time stamps in the logs can be vital
• Many applications that run on a server might use the system time to generation information they show to the user. Depending on the application, time can be critical (for example, knowing when a financial transaction happened)

I'm sure there are others, but having accurate system time is a standard responsibility of a system administrator. NTP does a lot of sophisticated things to this end (accounting and correcting for drifts etc). So those details statistics can help you troubleshoot any issues that arrise in fulfilling this role.