Why well off Londoners supported the need to build housing for the poor in the 19th century?

The well off city dwellers supported the need to build housing for the poor because :
(i) The existing one-room housing for the poor was a serious threat to public health.
(ii) They were overcrowded, badly ventilated and lacked sanitation.
(iii) Fire hazards caused serious worries. Moreover, there was widespread fear of social disorder.
(iv) After the 1917 revolution workers became conscious about their rights.
(v) It is also true that a large number of people began to recognise the need for better housing for the poor.