Reducing the security rating rate to 0 would mean HS entities can aggress and engage known criminals interloping on their space, without CONCORD involvement.
This returns the security paradigm into player hands, rather than relying on CONCORD as an NPC entity as a solely reactionary response.
Then the change will have no impact on you, except that you will be able to aggress 0 Security rating players in HS without CONCORD interference or security status loss.
Either way, the impact of your proposed change means that gankers that have an interest in maintaining their security status will use their 15 minute downtime to fly to the nearest CONCORD office and tag themselves back over 0.0 security standings, (instead of once they hit -2.0 or lower, and then buy the tags in bulk) while -10 gankers will continue to do things as they always have. Then all of the people who do stuff like the occasional roams into low will suddenly need to either tag themselves or grind everytime they want to roam so they don’t get harassed in Highsec.
Nonetheless, the point of my suggestion was to reduce the threshold of HS aggression against known criminals via reducing the sec status required to engage them without CONCORD involvement.