How are they dangerous, exactly? You seem to see a disadvantage to exchange-level stops (i.e. CME) vs broker-level?
If you are referring to GTC limit orders, I don't see how abolishing them reduces Trade through violations, since brokers will still offer GTC orders that are resubmitted daily as limit orders. The only real change here is the HFT get to jump ahead of your GTC order, either because their daily limit order will beat your broker to the exchange, or at best you will only have a 50% chance of being ahead of the HFT limit orders that were placed well after your original GTC limit order. Example : You place a GTC limit order a month ago to buy XYZ at 10.00 while the stock price was around 15. Back then HFT scalpers had no interest in placing limit orders at 10, since they had better use for their margin capital. But one month later as the market price has slid and started approaching 10.00, the HFT scalpers cannot easily scalp until your limit order is filled. This change by the NYSE eliminates this problem for HFT scalpers.