My wife told me to not use material softener near our sheets and towels because she read that it damages them? She says that she read this somewhere but I can come across...

She says that she read this somewhere but I can come across to find anything that can back this up. Can anyone provide a cooperation to some information that either back up this claim or refutes it? I started departing out the fabric softener when I do the sheets and towels (yes, I do the laundry) and immediately the towels are coming out stiff as a board. Is fabric softeer really going to break my sheets and/or towels?
Ironing and starch?
Answers:    Fabric softener won't damage your sheets and towels. Who could stand to dry past its sell-by date with a stiff towel? Or sleep on scratchy sheets!

Fabric softener will put together your towels less spongy, though, and since some of that stays on the fabric, it builds up over time. Once within awhile wash them short the fabric softener and use some white vinegar within the rinse. They'll be good as latest!
I be told to progress green and use...
It wont damage them, so you can hold on to putting fabric softner within the washer & have soft sheets & towels again! :)