Greybeards. I think this could mean wise people. At least the
common sense is to expect the old people to have accumulated some wisdom.

     The force which makes software development possible is, of course, 
enthusiasm, but it needs some heading.

     I am sure Poetering is very enthusiastic regarding systemd and 
highjacking the whole OS. He is concious to be developping a new OS. 
But, what's his role here? I think he is just the work horse. He defends 
the project as he sees it, but some wiser people at RedHat (or Redmond) 
may have the true heading in mind and, even he, doesn't know it.

     Wisdom tends to make people reluctant to start doing things; this 
is why the modern trend is to promote the young and deprecate the 
greybeards. But enthusiasm makes people blind. This is why a mix is... 
well... wise.

     Sorry for this poor man's philosophy.

     Didier