Peleton should redesign the treadmill. It is needlessly hazardous, and a few small changes could easily remedy the problem without compromising the envelope of functionality for the device.
But: I absolutely hate modern appliances with egregious safety buffers, as to reduce their functional envelope down to precisely what the designers imagined, and nothing more.
Also, and I realize this is an unpopular stance: Danger is important for children.
I'm not suggesting that we need to start giving kids industrial metal saws or machine guns as soon as they can walk, but we do need to stop hiding them from the world. Kids need to learn how to live their lives, and that means getting hurt and learning from it.
Our job as engineers is, within the above limits, to try and keep those lessons from being lethal, disfiguring, or crippling.