Maybe not honest, but if you're trying to get an approval, a partnership, a buyout or an uplist it might be better to go with "if you can't say something nice, don't say anything at all."

There's a difference between constructive criticism and destructive criticism, for example between, "you might not want to buy a Pinto because they blowup in rear end collisions" and "we might want to redesign the rear end of our Pinto's to protect the gas tank from puncture." In selling the Pinto, the best thing would be to keep your mouth shut, period.