Hence it's not a problem for them. Problems are what create business opportunities. In the Alta Vista days, I had a search problem (search sucked) but today I do not. If Google went away I would still not have a search problem.
Obviously, if something arcane like QoS became a problem for users, then an ISP would have a more difficult cost/benefit decision to make about how neutral it wished to be.
That is no point at all. Users are not familiar enough with the problem space to be able to care (or not).