I.e. that tenants should be allowed to spend their discounts on the open market, rather than being obliged to buy the home they are in?
It would make sense in expensive areas (tenants can't afford to exercise their RTB due to rocketing values).
It would aid geographic mobility.
It would aid social mobility.
It would free up a lot of social housing.
It would even keep the Tories happy (higher value council housing vacated in London would presumably be sold of us per their announced plans).
Generally speaking, it would do a lot of good.