Originally Posted by KlenTelaris

Upgrade of core of OS,(like moving from let say from cent os 6 to cent os 7) it's not needed, as all other parts which are usually required to run things can be updated to latest version without touching core of os.
This more sounds like they never heard for compiling. That is why i am not really a fan of package system as usualy you are forced to use specific version of php/nginx/apache/whatever and if you want to update by using package system you cant, only by upgrading whole os or compiling from source.