The notion of encouraging kids to push past easy doesn't bother me. Nor do I think we harm them by requiring them to do things they don't feel like doing. But I do maintain that parents should motivate their kids to stretch a little.
I respect Amy Chua for being honest in her memoir, and am glad that she's able to reflect on some of her parenting decisions with candor and even remorse. The conversation her book has precipitated is a crucial one.