Except the majority players aren't hardcore players. Making normal mode "harder" would address part of the problem where the midcore people have no appealing content because normal is too easy, while savage is too difficult. The thread you linked only addresses the state of PF and the lack of people clearing content, not necessarily the lack of people clearing savage (which as someone mentioned, is limited to 1-2 groups per realm on average).
My group is me and 7 other casual-to-midcore raiders. We grouped together with the intention of making a fairly lax approach to raiding with only three 3-hour raid days per week. Not a lot of time to raid, and certianly not enough time for retention when it comes to learning point-specific mecahnics. Having something like "people being more willing to teach" does not resolve the problem that we don't exactly have the people to teach in the first place. And this is applicable to most of the realms that have a relatively weak population (IE, not greg)