The flip side of this is that people will also leave because they get frustrated by having to either clean up after or repeatedly bail out the "incompetent but nice" folks, and will leave for that reason too.
And if you don't do it cheerfully, day after day, week after week, sacrificing lunches, nights and weekends, missing piano recitals and skipping vacations... you'll become somebody else's anecdote about a "brilliant jerk".
