In the early days for me (2004) I was aiming for about 1 in 20, I have kept this up but the quality has been improving. However in the last year I have pretty much dropped off traditionals as there are plenty of teams who can do those at nice places . Leaving me to concentrate on the things I like, and do best, "challenging" and creative puzzles, which take a lot more work anyway.
One thing however is that we should be tolerant of new teams putting out pretty average caches. It's part of the initial enthusiasm to just do it. It does take time and experience of about 100 to 200 caches to see the range of what's possible. With time I've seen most teams improve in quality and that's a good thing.
People should also understand the maintenance requirements as they can be substantial and effectively forever if people are still enjoying the cache find.
On the other hand the constant stream of emails from happy cachers who enjoyed the find make it way, way, WAY worthwhile.
Even when they wanted to kill you when trying to find it..
The thing that amazes me is the effort people go to to create a brand new park just to put a cache in when I could swear there wasn't a park there the other week, or for the previous 30 years