insane -19 nice level for system service (mailgraph) - is it acceptable?

[Bruno Wolff III]

On Wed, Dec 08, 2010 at 10:57:21 -0600,
  Chris Adams <cmadams at hiwaay.net> wrote:
> Once upon a time, Michał Piotrowski <mkkp4x4 at gmail.com> said:
> > 
> > PRIORITY=-19

> Why do you (repeatedly) call it "insane"?  That's kind of rude.  The
> process is running at a low priority level; do you have a problem with
> that?

Aren't negative priorities higher? I think this is running at the max
priority, not the min one.