Wut? o.O
"casuals" and "extremes"?
I think this is an example of someone being far enough out of the mainstream that they think the mainstream is more like them than it is.
Extremes are midcore content, and (depending on who you ask) on the higher end of midcore. No Savages are midcore aside from some of the 1/5/9 entry bosses for a tier. Generally speaking, casuals don't touch Extremes at all.
This is kind of like hearing a person who makes $500,000 a year commenting how everyone makes and spends at least $200,000 a year, not realizing the vast majority of the public doesn't even make six figures, and the poor sometimes don't even make 5. (There are tons of people that legitimately make less than $10k a year).