As others have said, participating in leagues and tournaments that match your skill set is key to enjoying the sport.  Trying to compete at a level that is way above your skill level can be masochistic.  It can also be a learning experience, but many times will just be frustrating.

There is a time and place for every bowler to have an opportunity to participate, regardless of skill level.  It is just a matter of matching your skill with the correct type of competition.

I have bowled in house shot, no-tap tournaments where card carrying PBA members entered and absolutely destroyed the field (shooting 1200 for 4-games).  The first time I figured it was just a fluke.  The second tournament where that happened was the last one I bowled in at that center.  I am a decent bowler, but not a strike machine like the PBA bowlers.  It is just a matter of learning when and where you can be competitive.  I have since stopped participating in any tournaments.  I would have no issue entering a local tournament if someone needed a teammate and invited me to join their team, however I am done seeking out and traveling around to tournaments.  Bowling is much more enjoyable just sticking with league and an occasional open bowling practice session.