I see both sides. I hate having to pay extra when I already paid admission and parking. But some attractions have rotten capacity. Also, it's a quick, cheap thing to put up that you can contract to run and maintain. They also take up very little space. But yah, I'd much rather have a new coaster than a couple upcharge rides.
With 1 exception: a Skyscraper. I'd definitely pay extra to go on that.
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Yeeee Haaawwww!