I (self-servingly) don't think that cynicism is bad, nor that it would be a good idea to pathologize what is simply a healthy defense to a hostile reality.
It depends on how you wield it.
Cynicism shouldn't cloud your judgement. That's the actually correct point you wanted to make, I think.
I tend to agree. The quote "It is no measure of health to be well-adjusted to a profoundly sick society" embodies it well.
I don't think cynicism is the correct approach though. It's possible to accept that circumstances are unhealthy without internalizing general negativity. It's just hard. I suspect you and I, and OP, are all agreeing with each other on this point.
Cynicism is a negatively biased view of the world. People should strive for accuracy. Sometimes accurate is also harsh, but that is different.
Maybe this is the same thing you intended by saying it shouldn't Cloud your judgment.
I try not to think in black/white, good/evil kinds of terms. I think of forces and dynamic systems.
There appears to be some force that promotes one particular way of thinking, perhaps the inevitable consequence of accumulated experiences. In the case of cynicism, the balance tends to shift towards one side of a scale over time.
Without a countervailing force on the other side it can tip a normally balanced system out of stable equilibrium.
My point is explicitly: the world provides the force in one direction, and the individual must provide the force in the other.