You should read the other books, but the short answer is that IEX was created not to save the common man, but to save the big block hedge fund traders.
There is a natural and good competition between HFT market makers who provide liquidity and big block traders who consume it. IEX is purpose built to advantage the big block traders at the expense of HFT market makers.
Note: neither side in this is good or evil, they are just natural opponents.
What I would say is dodgy is presenting yourself as "for the common man" when what you are doing is serving the common man up to hedge funds.
There is a natural and good competition between HFT market makers who provide liquidity and big block traders who consume it. IEX is purpose built to advantage the big block traders at the expense of HFT market makers.
Note: neither side in this is good or evil, they are just natural opponents.
What I would say is dodgy is presenting yourself as "for the common man" when what you are doing is serving the common man up to hedge funds.