It needs to also be there to serve the needs of the all the people who are struggling for space to live in our very expensive Cities.
No regulatory system can adapt quickly or regularly to the whims and fluctuations of the property market.
The fact that certain people in certain areas can't afford certain building work is irrelevant. What happens when these families need a bigger car for their bigger families? Should they be given one for free, should they steal one under the justification of "I need to because I otherwise can't afford to"?
What individual homeowners can or can't afford is no justification for allowing poor design at the detriment to an area and other people in that area
Don't confuse the two issues