When should we be contradictory?

Last week I read a post, not one I follow and I didn’t agree with person’s opinion.  It’s not like they said something that offended me, I simply disagreed with their example.  I wanted to politely comment and give my reasons why but I didn’t.   

Why not?

I didn’t want to come off arrogant.  Because I AM NOT, but you don’t know me and my comment could have been misconstrued that way.

I didn’t want to be the one person in the group that didn’t gush with praise for the brilliance in the examples.

I didn’t want to be the one person in the group to point out the flaws in their example.  It was a “show don’t tell” post and I counted five tells in their show.  Plus there were several descriptions of other things in their “show example” that were irrelevant descriptions thus slowing down the scene.  Nice descriptive shows but their irrelevance pulled me away from the importance of the scene.

So I ask you, when should we be contradictory?  I’m not talking about Negative Ninnies, just making points to the contrary in a unkind way.  I’m of the Southern Polite Sensibilities; “If you can’t say something nice, keep your mouth shut.”  (or that’s my version of it) Most of the time I agree with that statement because being unnecessarily contradictive makes you sound like a miserable person all together.  When I am asked my opinion, I’m politely honest even if I disagree, keeping my thoughts to a sentence or two.  

This particular post did not ask my opinion and what I had to say would have been lengthy to explain my reasoning.  I felt pretty passionate about my thoughts and opinions and wanted to share them but I didn’t.  In the end I asked myself what was the point.  If I don’t find this information/blog to further my writing, simply don’t follow.  The End.

But it doesn’t end there because it bugs me I couldn’t wouldn’t speak my thoughts.  I don’t want to be the person who always agrees but I don’t want contrary either.

What would you do?