I once got branded overly negative after my input at a few successive meetings. One group of users (who weren't knowledgeable about IT in any way other than knowing enough to be dangerous) had got into the habit of presenting detailed technical solutions to all and sundry and then asking me (the IT guy) if they would work. What triggered their complaint was when I told them in the meeting that it was certainly possible to code what they had described but since they hadn't described the business problem they were trying to fix there was no way I could tell whether coding them would help or hinder their goals.

As people have already said identifying the problem is the first step to solving it. To ignore the flagging of a problem because a solution hasn't been identified, yet, will inevitably result in hitting the same problem later when it's harder to solve.