The success of an upgrade can be measured by the length of time for which the complaints are trivial. It can't be measured by the number of complaints, which is a constant. Nor can it be measured by the first complaint, which is often irrelevant. Established technology tends to persist in the face of new technology. If you want to make something go away, you have to help it along.
Nothing is so good as it seems beforehand.
No program is so obsolete that nobody wants it anymore. No one can keep up with infinite change. The higher the rate of change, the more people get overloaded. Being a system administrator would be much easier without the users. It would also be pointless.