Windshield wiper springs fatigue?

I haven't seen them fail/fatigue much but some cars are weaker than others. IIRC Corrado owners had this problem a lot.

The springs on my 1970 Bug were still good 18 years after I bought it. I don't think it is a serious problem. What I do notice is that few people bother replacing the blades as often as they should. That is once or twice a year for me, your mileage may vary do to environmental conditions. Just because the blade is in one piece does not make it functional.