It is a widely appreciated value. I rarely see anyone advocating for dishonesty.
Honesty can be tricky. When making a product, you can be honest in the sense that you do not intentionally lie or deceive, but dishonest if you make some information harder to find or use some patterns that encourage some behaviour contrary to the best interest of people using it.
In our work, honesty in its most strict form necessarily leads to transparency, which most companies are still afraid of.
The advice is usually that people should not be vulnerable to their employers as a form of self-protection. There are laws against employers requiring or even asking for some personal information, it is not something we should take lightly.
I remember a talk by Sergio Diaz in which he talked about being vulnerable as a leader. It is one of the most insightful points of his talk or at least one that resonated with me.
And it makes sense that in a relationship with unequal power the one with the power would be encouraged to be vulnerable, and those without the power would be advised against it; especially when those without power are vulnerable in other ways.
Being vulnerable is a powerful tool when it is by choice; when we can choose how, when, and how much vulnerable we are. It can help build trust, and make relationships at work more human and emotionally healthy. Being allowed to be vulnerable by someone else leading by example creates a more welcoming environment.