Some theories: 

• They’re very long. Can we accomplish the same goal in a shorter time? 
• They meander. What are we trying to accomplish here?  Is it compelling, or even clear?
• The people. Is everyone prepared? Do we even have the right people here? 
• The organizer. Leading a good meeting is a skill. Does the conveyer have that skill?

Perhaps most importantly is why so we have meetings in the first place, what could we do to accomplish just as much (or more) without so many meetings? 

Some theories: 

• A process for making decisions is not clear. We have to meet if decision authority is split, or, debate is required. 
• Information is asymmetrical. We have to meet if (or do we?) if information needs to be shared. 
• I don’t trust you to do your job. We have a meeting for “accountability.” (This is humourous, because meetings make it difficult to do our jobs!)
• Working through a problem. We each have something to bring to the table that is not easily activated without human-to-human contact. This is a great reason to have a meeting.
• Efficiency. Borrowing from Paul Graham, meetings are efficient for managers, but not for makers. 
• Hierarchy. If someone with higher ranks asks you to attend a meeting, you have little choice to skip.  

Why do you hate meetings? When are meetings totally worth it? What’s the best meeting you’ve ever had? What’s the worst one? 

H/t to Liz for the point about split decision making, I never thought about that.