I completely agree.
But it's still possible to respond neutrally, truthfully, and informatively.
For example, it's possible to just answer with positive aspects and leave out the negatives--that's still valuable info.
Or someone can honestly talk about whether the culture is, for example, high-energy or more laid-back -- each has its advantages.
Are you saying that it is _not_ at all worth cold-emailing a peer in a potential workplace?