Higher points cost would be one factor, but I agree with the villain that the lower cost of high rise developments compared to low level is probably the biggest single reason.
As well as no mention of consierge I didn't see any mention of dedicated restaurants for the BLT. I saw a members lounge mentioned, but not a restaurant. It also seems the pool would not be a "feature pool" in the manner of VAKL and just one extra pool as opposed to the 4 or 5 at DSSR. All of those tend to be a cost items to running a resort, therefore increase the dues costs.