If you have something bad to say about something but have nothing to say when it comes to how it could be better. I think that it’s a useless criticism.
It’s easy to be a critic or to complain about the way that something is but what’s the point if you can’t even offer a solution.
It’s far more useful and far more helpful to say ‘I don’t think this works very well but here’s what I think would work better…’, rather than just saying ‘That’s not a good idea’.
I think what a person says comes down to their intention to speaking up. Do you just enjoy complaining or do you want to try and find a way to make things better?