Think of it as playing poker with your cards facing the table. You are showing your hand to the HFTs purchasing your flow. They can lean on your order to trade in front and scalp around it knowing their downside is just your limit if the market goes against them. This also means you may miss fills as others trade ahead of you and giving up a good chance at price improvement if available.
You lose on potential price improvement but gain on the definitely lower commissions. Further, if you are a profitable trader, wouldn’t you want to be lumped in the bucket of people who are considered unprofitable? Retail order flow is sold because the customers are statistically unprofitable. Why highlight your trading prowess by accessing the market directly?
If you are trading size that HFTs can lean on then: 1. You are not using any retail platform; 2. You are breaking/working your orders. You are playing a completely different (professional?) game. But if you are a piker (like most of us here), you don't have access to technology (Colo+speed) to circumvent/outsmart HFTs/MMs. Give me an example of a retail platform where you think you will avoid HFTs with your internet connection. What kind of strategy are you running that requires you to complete with HFTs/MMs anyway?
I would not categorize it like that (although it is not wrong either). I would call it riskless to the MM. @Robert Morse would know more, but I would say that MM will make money either you are statistically profitable or not. As long as your timeframe is longer than a few seconds, you should not be concerned about HFTs/MMs, imho. Now if your strategy requires re-price every time underlying ticks, you should definitely not use RH.
I assume we are still talking about Listed Options. I would call all market orders of any kind that is not a "pick off", to many to define, good order flow that a MM can make money off. There is too much focus in forums on what your counterparty will get from your order and not enough focus on finding an edge. WIth us, you either want to use our SMART route to avoid Maker-Taker fees or want to direct your order to have control over what exchange you hit and what those fees or rebates are. If it were me, I would want the choice, but I would make my default SMART.