If an umpire is destroying years of hard work as a vendetta then I can't say I blame the girls or the coach. I blame the guy that isn't being fair in his officiating.
If it's OK to bean an umpire as payback, then what is wrong with an umpire having a vendetta as payback?
Both are wrong, of course. I suspect that you have issues w/ umpires that are making it hard for you to see this objectively.