Ok, I've been sewing forever and a week and have used all sorts of fabrics for all sorts of purposes.

Why is there such a definite prejudice among quilters against polyester and poly/cotton blends?

Is it a matter of 'staying true to our roots' or something else?

Or is it related to different ironing temperature required if you are going to use fusible web for applique?

So far I haven't encountered any noticeable difficulties using fabrics of unknown fiber content in my quilts (some of which I suspect are 100% polyester), so I wondered what is going on.

I do not like the feel of the '70's double knit....clothing or quilts. My DDIL loves them. The ones I had I sent to her it's a win/win deal:)

I do not usually prewash, so mixing cottons with poly or cotton/poly blends could be disastrous LOL
BUT if I had a blend that I liked, I would prewash and not have any problem using it :D:D:D

There are no quilt police :) Ironing temp certainly could be a problem if the fabric has polyester, but if you know that then just iron it on a cooler setting. I have a very old quilt from my great aunt that has all different kinds of fabrics ~ cotton, taffeta, and who knows what else. One of my very favorite quilts is all polyester from the 60s and 70s left over from dresses my mom and I sewed. It will never wear out although I think I may someday have to replace the backing which was a used sheet. Some quilters I am sure are purist, but I think it is up to you and your purpose.

back when I started to quilt...I used whatever I liked...
Now, I know about the way that different fabrics hold up and wash and shrink...

No quilt police-I just don't like the feel of poly and it pills sooner or later.

When I first started, I used what I had, which included blends that felt like cotton. I don't (and didn't) care for all polyester, and I think now I tend to go 'all traditional', but, especially for heavy use ones, there's no reason you couldn't. Besides, it your quilt - make it as you wish! No quilt police here!

Not really sure what caused the big concern is either. Various reasons,
1.) some folks only want to use "natural" fibers,
2.) some are concerned about the different fibers will wear
3.) others that do not pre-shrink their fabric are concerned they will shrink unevenly.
I am sure there are other reasons.

Sometimes I can only find a certain shade of a solid fabric in a cotton blend, so that is what I use. So far none of the folks I have given a quilt to has had a problem.

There are some Poly and blends that will beard and/or pill. I don't as a general rule use blends but don't have a rule against it, infact there are times when a blend will outperform a 100 percent cotton. Absolute black is one of those times. A 100 percent cotton black fabric will loose color faster than a blend, in side by side wash per wash testing. I have done my own testing with swatches from different companies ...different lines.. throwing the swatches into the same laundry loads every time ...... and yep a blend beats it( 100 percent cotton) hands down in the which black will stay black longer test.
Quilts were orginally made from what was on -hand.... I follow that lead ...

If you like it, go for it. However, poly and poly blends do not show quilting as good as cotton. I just use these items for household decor.

I've made some quilts to use up poly and poly blends and then use flannel on the back. Pretty common with children's fabrics since many character designs only come in blends.

However, if you were involved in a swap, I would definitely make sure it is 100% quilter's cotton.