The point you provide is very well understood by many, it is quite obvious that some guys are better than others when it comes to tuning/setting up engines however, it is very unfair to label all as incompetent. The proof is in the pudding. Believe it or not there can be bad engines!
The determining factor here is proven by the numbers, if 60% of the members cast vote on engine X being no good or be it "hard to tune" chances are they are not a user friendly engine. This would be considered upsetting seeing as though 80% voted on engine Y being great.
We don't want a magical engine buddy we want reliability from beginners to advanced !
Enjoy your choice in engines for your given airframes.