The situations you describe sound familiar but, even though you've experienced these things in 3 leagues, you have to remember that in a small sample size anything can happen. I've been in this since the CSN days and I've seen some really strange things happen; unknown or just bad pitchers shut down good lineups, great pitchers shelled, etc., but I've seen this in MLB too. My Yanks lose to mediocre pitchers a bunch of times each year, but over the long haul they're pretty good. Same in PB. I haven't seen bad teams win perpetual league Championships; over a full season things even out and the cream rises to the top. In LL's anything can happen, but usually the Champs are one of the strongest teams.
Lastly, while game play is paramount it's not everything. The interaction with your fellow owners, the trade talks, the friendships you develop are just as important to a great experience. I've had a blast and plan on staying with it for a long time, give the full experience a chance and you may grow to love it too.