Pachter or not it's a true statement. Accessible, fun, quality games. Although the more mainstream audience has a different opinion of quality than the core audience.
Zack & Wiki is a great game but not one with mainstream appeal. Just Dance is a success because it nails accessible fun. Havn't played it myself so I can't comment on quality but judging from how owners defend it, it obviously achieved what it set out to do - in spades.