I've only hosted one comp and put it to public vote because i thought that is the norm here.
I was super shocked when a Host announced i'd won a comp and she was the only judge.
I know i can speak for many newbies to DUP
when i say i had no idea that a responsibility of of Host is to Judge, as well, and i would have in that comp i Hosted had i knew.
Selecting your own winner contributes to your growth as a poet in so many ways: firstly, it holds you accountable to read each entry thoroughly vs just leaving it up to the public ( and we always learn something from reading another's work ); secondly, it demonstrates just how difficult it is for hosts when they do select winners, especially out of so many great entries that you, as a writer, know they put their best into; thirdly, you gain experience which contributes to your own participation in competitions, appreciating in more depth the responsibility of the host/ess, and therefore understand more aptly that not everyone can win.
The latter is probably something we all know innately; however, actually being in that position to choose a winner ( or assist if you opt for a panel of judges ) allows you to experience it first hand, and perhaps take it much more seriously then simply allowing a public vote.
Though I certainly understand the nervousness associated with being new, at least until you get your feet wet. I think it was two years before I held a comp.