JCWolhschlag - I've used spiderwire to sew a variety of items and have never had any problem. For example, I sew leashes and collars for my dogs using webbing and spiderwire and have never had a problem with cutting. The leashes get a lot of stress put on them. But, to be fair, the webbing is usually made of very tough fibers so they would be hard to cut.
I have sewn or repaired backpacks and bags made of cordura and extremely lightweight siltarp using spiderwire without any cutting problem.
That said, I wound imagine that if you sew a button onto a cotton shirt by throwing a few loops of spiderwire and the button gets yanked that the cotton cloth will fail before the spiderwire would. I don't know if that is a good thing or a bad thing.