Say no to Stihl oil?

I've been a Stihl guy my whole life. And as long as I can remember I've been buying Stihl oil especially to double the warranty on my new saws.

In several posts lately I've seen lots of people saying to avoid Stihl oil and to run a more oil rich mixture. What gives?

I am usually of the opinion that the engineers who design this stuff are way smarter than I am.