I agree that these ads are showing unsafe use. That said, you can only (mostly) hurt yourself with a kayak. A car can hurt other people in many ways. It's the same story with a bike.
While I take your point, mostly is doing a fair bit of work - SAR can be a dangerous job. Get swept out to sea and you might be scooped up by a Coast Guard rescue swimmer. Repelling or jumping out of helicopters might be their day job, but it's not exactly risk-free.