The point isn’t that the costumes are modest. The point is that such immodesty is on display at friday night football games across America.
Well, I agree about the general trend in slut-inspired girls’ clothes being much more widespread than just Halloween constumes. (Catholic school uniforms, not so much.)
But I think Rebecca Hagelin’s larger point is that Halloween is becoming much more a whiskey-bar adult sexy dress-up (reaching down into teens and tweens) rather than a Snickers bar-ghostyspook entertainment for kids.