Why do we Built so Vulnerably? †

Added to Rightmove yesterday were these two adjacent semis, each available for £139,000. Cavendish Ikin's particulars state that they have recently been refurbished—this no doubt thanks to the January 2021 flooding, The agent says, 

'A newly refurbished two bed semi detached house located just off the lower part of Clwyd Street close to the former town mill and the Cunning Green' 

Well, the Cunning Green'll be closed for some months. And the rest, translated, means that it's in a flooding zone that the current NRW prevention works will mitigate but cannot fully prevent. 

Why do we still build in such vulnerable areas?

† Deliberately grammatically ambiguous