Just a quick skim of it from wikipedia and it's a data gathering program to implement price control regulations from the LBJ era.

"Under the rule, any jurisdiction that receives money from HUD must analyze its housing occupancy by race, disability, familial status, economic status, English proficiency, and other categories. It must then analyze factors which contribute to any prohibitive barriers in housing and formulate a plan to remedy the impediments."

As to why that may not be beneficial, I'll bet Thomas Sowell would have some things to say about it.