Older polyester threads were a thing to be avoided. I have sewn since the early 70s and when poly came out, it was miserable to sew with, especially to hand sew. It snarled, knotted, broke, and was just awful. Today's polyester threads are a whole different animal. The improvement is phenomenal and I have no problem adding them to my thread stash.
Re: a quilt isn't "real" unless it's hand quilted. I first became interested in quilts in those same early 70s and that myth was more prevalent then than now, I think. Again, the improvement of machines, tools and general know-how has brought a new attitude among many (most?) quilters today. Certainly hand quilting still has its place, but our foremothers would have used sewing machines in a heartbeat if they had them. I, for one, am very glad to be able to toss a quilt into a washing machine and not worry about its stitches coming apart — what a blessing!