Whining wipers

A wintry tale

I should not have been surprised, should I?
The windshield wipers on my Mazda 3 started to whine and screetch during the first storm after I had my windshield replaced.
They'd not done that before so when the guy asked me if I wanted to replace my old wipers with new ones at the same time that I replaced the windshield, to "protect it from scratches," I turned him down.
I said "No, thank you. They're good."
I like to think I'm savvy.
I figured it was just a way for them to make a $20 upsale and I was already smarting from the replacement costs.
But, at the first sign of snow and rain the other night, I regretted my thrifty decision.
The wipers howled and annoyed me as they tried to keep up with the snow falling all the way from my home to Eagle Mountain.
It got so bad I just shut them off and took my chances at peering through the snowy glass.
I went back to the windshield store and told them I was wrong, wrong, wrong and would they take my $20 and give me new blades?
They agreed to do so.
After about 20 minutes and an exchange of cash, I was ready to be on my way.
But I couldn't resist asking the guy: "Why would blades that had been working perfectly well suddenly start to be such a problem? Is the shape of the new windshield different?"
(I'm wondering if maybe a repair person bent them when he was replacing the glass?)
"Oh," he said, taking off his glasses and looking closely at the invoice.
"It happens quite a bit. You have this new, clean glass and the wipers are used to working on the old, rough glass. That causes some noise."
I must have looked skeptical because he continued.
"And, you know, in Utah, because of all the snow and cold and the salt we put on the roads, wipers only last about six months, anyway."
Or about two days if you turn the dealer down at the time of the replacement, right?