Right in the middle of a cycle path is extremely obvious though. You basically have to not be paying attention for an extended period of time if you want to run into them.
Still, it happens, and the designer of the infrastructure must be aware of that.
To take the devil's advocate role, people will keep traveling long after they exhausted their ability to pay attention, and/or keep reasonable distance from the next one in the front.
While this is true, we haven’t stopped selling knives because a few people use them irresponsibly. By the same token, we shouldn’t discount infrastructure because a few people drive when they shouldn’t.