Real world value does not change in millisecond increments, except for earthquakes and nuclear holocaust. Therefor the profit in HFT is extracted by decreasing value for non-HFC entities (that would be you). It's analogous to entropy.
The value extracted by the insiders disproportionately degrades the system for everyone else. It's equivalent to oil production in the Nigerian delta. The people who live there have a horribly destroyed environment, and people far away make huge profits.
HFT is vulnerable to mistakes and deliberate manipulation. Can you say Flash Crash? Remember, there is no real time way to tell the difference between a misbehaving algorithm and a deliberate market manipulation or a hostile attack. It's not even clear that you can differentiate after the event is over.
Anyone with a shred of self preservation should be scared shitless by this situation. For Wall Street HFT is a sacred institution, and any attempt to reign in the abuse is treated as an attempt to defile a holy site. They own the casino, and given the centrality of international banking institutions, everyone is forced to bet no matter what.
Wall Street types should be treated like meth freaks with rabies, because that's how they behave. They are actively dismantling the world economy for their own individual gain, and if they are not stopped there will be nothing left to save.