Those who feel the need to inflate their ego by criticizing others without offering a solution are inflating the ego of the party at the other end of the table as well.
Perceived as a total waste of time, the advice unasked for will be met with resistance. Lots of it. Inflating the ego of the receiver in the process.
There is a minuscule chance that some value can be derived from criticism, even without alternative solutions. Maybe it sparks some insights or forces the narrative to be altered.
However, without clearly stating what the purpose and desired outcome are of the criticism session, the risk of all egos involved looking like pufferfish is substantial.