An open source project is as good as dead without users. Whether they are complaining or not, if someone gives you a piece of their valuable time, that should be appreciated.
Users are only as good for the project as their reinvestment in the project. A small number of users who contribute code, money, or bug reports is better than a large number of users who never interact with the maintainers. In most cases the number of overall users is correlated with the number of contributors, but it's the latter group who are driving development and growth. A large user base is more a side effect of a successful project than a driving force.
may be, you are right, users are as good as their reinvestment, with regards to open source. However, reinvestment doesn't necessarily have to mean code, money, bug reports or something similar. It could be as simple as, spreading the word. I really appreciate those who share their experiences with a project. It helps make long term decisions easier.