On the application it says the properties will be available for sale or also to rent. I suspect rental is the real purpose - to the council.
As you say there are some lovely Victorian properties - it's criminal to destroy them - especially to replace them with modern multi-family buildings.
They cite the flats on the corner of Normanton Road, and the proposed development at the corner of Aylward Rd & Sunderland Rd as precendents, and yet neither of those properties was a period dwelling - the Normanton Rd site was previously a garage/service centre, and the Ayldward Rd site was a horrible, pre-fab, post-war bomb-damage-replacement 2-storey maisonette, which is being replaced by two 2-story 2 bedreoom houses. I.E., they are pretty much replacing like-with-like, and not destroying a large, period family house with 11 modern flats!