I agree I think it's bad form to call a manager out on a bad trade offer, but there is one case where I will make an exception to that rule. That is where the other owner is calling me out or generally smacking my team; at that point I consider it OK to call out his absurd offers in retaliation.
E.g. "Beat it clown, at least I don't go around making 'serious' offers like Luis Castillo and Brady Clark for David Ortiz. Good luck with that. I hope you are getting comfortable in 14th place.."
You've got a diamond, You've got nine men
You've got a hat and a bat, And that's not all..