There are times, as pointed out in several posts, where almost anyone is going to dislike league bowling. To me, it is the social aspect that will make or break league bowling for each of us. If you like the people and the environment created by the league, chances are you'll enjoy bowling in the league, otherwise, you won't.
Both 'Bones and Pinbuster raise good points: most of us are a product of our times and all of us are subject to burnout at one point or another.
Finally, some people just aren't geared up to the "team" mentality, regardless of the activity. Witness the popularity of the "X-Games" and other "extreme" sports where there is little or absolutely no concept of team. It is all individual performance.
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Kill the back row (or maybe this should read "make your spares, dummy")