The "kids these days are lazy" is such a nonsensical thing and it's nice to see it de-bunked here. That kind of talk is the excuse of a poorly run company.
The whole "Six Flags is understaffed" seems like a relatively simple thing to me to diagnose. Maybe not fix, but diagnose. The company pays horrible and is horrible to work for. It's that simple. Also yeah, being out in Eureka does somewhat make it harder to find kids than say, somewhere in St. Louis county, so we can add bad location to to those other two, but I think that's a bit of a lesser thing.
A company operating a theme park can probably get away with paying crap to bottom rung employees moreso than others because, at least in theory, it's a fun job that has cool perks.....if it treats its employees well. Six Flags, as noted in the example posted by Kim above, does not.
I don't know what kind of culture Cedar Fair has at their company, but I'm hoping at the very least it's an improvement over Six Flags. That alone would help improve park operations here, though that kind of thing takes usually a couple years. Given how seasonal a theme park is though, if the right people are put in place in management a turn around on that front can be probably happen quicker than other types of businesses.