well, the extra is actually less than 3,116, because the business class ticket in your example earns the 25% J bonus, but not the upgraded segments in this Shanghai Pass (officially, although I have heard my colleagues have got it)...

but I think there could be a couple of reasons this Shanghai Pass is better:

• people trying to qualify by sectors instead of miles (i.e. 6 sectors instead of 2.5)
• people requiring 0/30D min/max flexibility instead of 2/7D (I often buy same-day or one-night tickets and usually most discount tickets require 2 nights)
• the HKD 1290 fare actually is quite restrictive in terms of flight choice (if I remember right), while this fare should give quite good availability on all flights (availability of H class usually not bad)