For one thing because now people who own high-speed low-latency connections to stock markets have no advantage over "normal" people who actually do meaningful work, like being a policeman or nurse.

Price discovery and increasing liquidity is meaningful work.

>people who actually do meaningful work, like being a policeman

Making a sudden event that happened on the other side of the world reflect in the local market price at almost the speed of light is far more meaningful work than going around shooting dark-skinned people.