I think, that the wording used defines bashing, or telling of positive/negative experience.
If for example a carb has been quite contaminated with locktite: (happened to one of my customers) he could say:
1) that engine is a load of crap! I swung my arm out of function trying to start it and never got to run it right! (Etc, more offensive stuff)
or
2) I had a carb issue (explains ...). The dealer first would not believe me, but finally we solved the issue.

The first I would consider bashing.
The second is problem reporting which helps us all understand the products we have in use or plan to buy.