Trying to compare the whys between resorts is often a difficult process but some points:
(a) BLT is lower than any mainly because the points needed per night are the highest in relation to other resorts(and super high in some respects in comparison to other WDW resorts) , and that means they are selling a lot more points per unit than other resorts and thus are able to charge less per point in dues.
(b) Resorts connected to full service hotels are generally higher than SSR or OKW because dues are paying for services you don't see at the stand alone resorts, including such things as valet services (people think valet is a perk that is free to
DVC members; on the contrary it is "free" because you are paying for the operations and employees who make up that service up front in dues). You may think newer less maintenance, older more maintenance but that is not necessarily true as mainatenance is always an ongoing process. Moreover, what many don't realize is that the operations you are contributing dues to are similar to many business operations -- vast majority of all costs are employee (or outside personnel provider) costs. You are paying their hourly wages, their health care costs, etc.
(c) AKV is connected to a full service hotel and it has two additions to dues others don't have, care of the savannas and animals and concierge service (yes, those who don't get concierge rooms are contributing to the cost of concierge services; in fact they made a point of expressly pointing that out in the disclosure documents)