There's no reason to invest the development dollars into renovating STS into 64bit with native samplers having the advantage in terms of access to local pools of ram, disk streaming libraries into the gigabytes, and so on. If it came magically with addressing some of the other 64bit bugs, it would still show that AKAI samplers from the 90's have long been eclipsed by modern native solutions. If S|C ever decided to create a device akin to the standalone Akai MPC units and Push 3 etc (all of which integrate a lower power native computer), great, but with other priorities being higher for our community I don't see it happening soon.
Nothing is stopping someone else from creating a new company to create this product, and finding out how much demand there is in the market for it in terms of dollars (rather than in terms of online posting).