It will be cheaper to engineer a die-off via covert bioweapons and such. From the perspective of the superclass, why give useless eaters money when that money could be invested in the consolidation of power?
So I believe the superclass don't want their subjects dead; they want them submissive, healthy enough to work without dying, and happy enough to not be motivated to try to change the system.
P.S. from a certain POV, money itself is a consolidation of power. The superclass uses money as an enslavement method -- see how most of middle-class are constrained to wage-work for paying back their debts.
That's not easy-- how does one keep that kind of secret while setting it up?-- and the precedent it sets is dangerous. If the non-elite are all killed off, then most of the remaining people (formerly elite) are non-elite and the cycle repeats.
The same as with any controversial program. Claim the program is intended for non-domestic purposes, compartmentalize the development into different complimentary components, perform controlled leaks about the development that allow you to frame the public perception of the program (and makes it "old news"), and discredit any public "conspiracy theorists".
>If the non-elite are all killed off, then most of the remaining people (formerly elite) are non-elite and the cycle repeats.
Enough non-elite should be retained to keep the lights on, provide security, and serve any unforseen purposes in the future.