I think so, too. A machine uses whatever I put into it, or I'll find out what's "off" and make it work.
Of course, I don't try to use hand-quilting thread or rope in the needle - there are some things that a domestic sewing machine will not do.
But lots of times, I see people saying that their machine won't take anything but "X" brand of thread and I would take that as a challenge. I would want to tinker around and figure out how to make it take the kind of thread they want to use. Usually it's only a matter of changing the needle and/or balancing the tensions.
If I ran across a lot of reviews for a machine that said, "You can only use X brand" in this machine, I just wouldn't buy it.
I see this a LOT with longarm machines - and as much as you pay for a longarm, that machine better sew whatever you give it to sew!
