To be fair, Quidditch history is peppered with vigorous resistance to change. It's relatively recent that they even started wearing helmets: they made a new edition of QTTA to include it. I think it goes back to wizardly pride in our own hardiness. We preserve the danger by insisting it's not really that bad, despite making plenty of jokes about "one too many bludgers to the head."
But innovation in broom design tends to be the exception. I'm not sure how you'd get that working, I'm no broom mechanic, but I could see that making a big difference.