You would be surprised. Those most affected are the ones who fly scale aerobatics in competitions called IMAC. Basically, its an R/C, scaled-down version of IAC competition. 400' is incredibly easy to exceed during any of the vertical maneuvers, and large loops. Also, glider pilots would have a tough time staying below 400'.

As for speed, 100mph isn't really that fast. Many basic sport planes, just 1 step up from a trainer can hit 100mph or more. I currently fly a turbine-powered jet that can easily exceed 200mph, however I am limited to no more than 200mph per AMA rules.

The bigger point here, is that none of these recreational models are capable of flying on their own, or beyond the visual line of site of the pilot. This alone makes them significantly less of a risk (regardless of their performance potential) than the multi-rotor "drones" that have caused this problem for us all.

As an ATP myself, who relies on flying an airliner to make a living, I have just as much of an interest in safety as you do. As I said earlier, I am all for regulating the "drones", I just don't want the "traditional" modelers to get lumped in with the bad apples. The traditional modelers have operated their models in harmony with full-scale aircraft for the last 80+ years without any issues, so it really isn't fair to drag them into this. The explosion of the "drones" in the last few years is the big risk, and undoubtedly needs to be addressed, but leave what is well, alone. That's all I'm saying.