Are you saying it's "dismissive" to express a negative opinion without supplying a raft of supporting arguments? A person can express an opinion without giving

Are you saying it's "dismissive" to express a negative opinion without supplying a raft of supporting arguments? A person can express an opinion without giving a dissertation; it does not imply arrogance or vacuousness. To say they are "dismissive" implies they expect their opinion to hold sway without discussion.