Earlier quoted context omitted.
Well just to clarify a little. There are 2 different concepts that sound sort of similar. 1) A dark pool. This is just another name for an exchange, but one that is not public. I don't know if NYSE runs one, but it wouldn't be surprising. The theory behind these is that they are provided as a service to large institutional investors to trade with each others outside the vagaries of the public markets for lots of reas…
The case we are talking about however, I believe, is where NYSE operates an apparently public market with delayed quotes for some players. Tptacek claims that my orders cannot even make it into the supposedly public market because someone will scoop up my order on the way, before it even reaches the delayed quote market and therefore, the market is not special because I cannot access it (which is disputable).
This is the case for retail orders, but not for trading firms. Prop trading firms don't tend to route their orders through wholesalers; they have deals with execution platforms (or implement their own) and route their orders to exchanges.
But there's a whole 'nother set of reasons why we're not especially concerned about competitions between prop trading firms on speed/latency/whatever: if they're impacted by HFT at all, they're competing in a zero-sum game to arb prices, and there's no moral reason why a slower trading firm is entitled to some equitable share of all the available profit from some arbitrage strategy.