The first reason is straightforward: it is just basic human decency to make hiring more fair.
The second reason is a bit less obvious: it is good for your business in a very direct way.
There is huge shortage of talent in tech, but the common hiring process is discouraging big groups of people that don’t match the stereotype of a programmer, like women or people of color. This leads to those groups being under-employed.
On average, you need to pay less for the same talent, or you get higher-quality talent for the same price.
How much time will pass before this becomes common sense?
Read what Dan Luu writes about data on discrimination.