It is true that cheerleaders when treated wrong will disappear and critics will weather the storm with you, it is with the caveat, in most context.

In the context of corporate culture and internal critics, I have seen numerous occasions when critics have left after weathering the storm when corporate bosses do not share the same passion towards users (employees and customers). In such scenarios critics have little to no control to implement fixes and are labelled negative under the definition of not meeting business goal (read: does not make the boss look good).

This may very well be because 'in American culture, that criticism and negativity go hand-in-hand', tho, I think this is unlikely.