Mixing oil is definitely a minority opinion. Oil companies do it all of the time to make a semisynthetic, but they prefer to overcharge you for their mix rather than have you experiment with your own mix, and maybe blame them for any bad results.
I agree with Mark Lawrence at his Calsci motorcycle site (a quote is below), after my own testing for shift and clutch feel and oil longevity. Note that I change my unusual mix at least every 3500 miles even though it is a semisynthetic:
"I'm sometimes asked if it's ok to blend your own oils. Yes, it is. Oils are all made out of pretty much the same chemicals, and nothing really bad will happen. If I wanted to blend my own oil, I expect I would use something like 25% Motul 5100 10W-40 and 75% Chevron Delo 15w-40, which would get me both the advantages of a lot of diester stock (5100 is pure diester [I think he meant 7100]) and the diesel additive package. In the winter, however, I would use 25% Motul and 75% Rotella synthetic, to get the superior low temperature performance. In fact, I just run Rotella synthetic in everything I own, year round: ST1300, DL650, Superhawk, Chevy Silverado, motorhome."
Larry constantly attacks any idea he does not agree with.
“Do…not waste time protesting the self-inflated showmen and bloviating bullshitters who populate our culture. It’s more fun to marvel at them, to appreciate them, to be grateful for them, and to mock them relentlessly. ”-from the 2010 book American Freak Show by Willie Geist. "He wondered what difference any of it would make two hundred years from now." -from the book Cyclops by Clive Cussler.