Too funny...as a parent, I can't help but to view your father's response as one of those axioms that I catch myself spewing while trying to dissuade my kids from entering (what I perceive as) less the stable environments. We all know that those environments, and the challenges that lie within help build character with every win, loss and push. Sometimes, it gets ugly.
It still scares the crap out of me to allow them to fend for themselves, but after stepping back and viewing the results, all is good - and it didn't really need me to run interference. For instance, I had to trust my (then 17 year old) with the well-being of my 12 year old in bars and clubs when I couldn't be there for all aspects (load-in, gig, load-out) of the show. Talk about nerve-wracking...but now, 4 years later, they both understand and respect the terrain in most of the clubs they play in.
If you would have told me 13 years ago that I'd let my teenage kids play in 21+ bars, I would have bet you money that you were wrong.