Different knives for different things. It's not hard to chop more onions or apples than comfortably fit under an 8" knife. If that happens you either need to work in batches or use a longer knife like the monster in the article.

If you're going through 10+lbs of veggies every night, the longer knife starts to make more sense. Still seems unnecessary for home cooking though.

You are not alone. There are people who prefer medium sized knives.

I like a 3", 5", 8", and 12" in my stable.