Suspect someone's been told to clear their stuff out of a rented flat above or lose their deposit. Maybe.

FH is still relatively cheap by London standards so plenty of DSS type lettings. Transient people with more fundamental things to worry about than the gentrification of the local area. (Generalisation I know)

We have one on our road, constant change of tenants, means a constant pile of c**p and new flat-pack packaging by the bins. The housing is probably temporary for them and they have no transport so they can't go to the tip, and have no incentive to research council collection services.

Not sure what can be done about it really other than for those of us who do live here longer term to report it to the waste collection people.