Base settings are just that...a starting point.
I agree.
The basic standard settings are in the middle of the road.
Dealers pull a new saw out of the box, fuel it, start it up, and don't realize how many variables that saw may encounter, depending on where they are shipped to on earth.
Temperature, humidity, altitude, and not to mention what formulation of gasoline is produced in that area. Not to mention what kind of oil mix was used, in what ratio, how long it's been stored, and what condition the gas can was in, plus how long the gas sat in the storage tank at the quickie mart.
I've seen many a burnt up piston from people trying to save a few cents by using some cheap chinese 2-stroke oil they bought at the Dollar store, or boat oil mix.
It amazes me how some of my customers will go buy a $1200 saw and use a gas can they found at the dump that has a spout that points upward, leaks, and sets in the back of their truck 24/7, rain or shine.