Just something to add: The very nature of insurance is to spread the cost of medical care across a large group. The odds are that a minority of those within that group will need medical care, but since that care is so prohibitively expensive, it's worth it to everyone to pay a small amount so in the unfortunate event they need care, it'll be covered.
Within any group, individuals all assume a certain amount of risk in their lives, whether by engaging in activities with inherent risks, or at the same time, by engaging in no activities at all and the resulting health issues that result. I ride motorcycles, hike, and scuba dive, activities which certainly carry risk. But at the same time, they're indicative of an active lifestyle which has health benefits. I have friends who's primary activities are drinking and watching TV, things which, while immediately less risky, carry significant health risks long term.
Some people don't brush or floss their teeth, and are subsequently more likely to need more dental care. Some people have terrible diets, and are subsequently more likely to end up with diabetes. By fracturing the large group into smaller pieces to tailor coverage to individual activities and/or lifestyles, you remove exactly that which makes insurance work - a large group over which a cost can be spread without prohibitively high individual premiums.
As motorcyclists, we are already in the minority, and already assume a significantly greater risk than everyone else. Turning on a small subset of our own group would give the general population perfect justification to turn on us as a whole. We willing accept more risk by riding as opposed to driving, so why not allow insurers to not coverage injuries sustained in our chosen activity, regardless of the gear we wear?
You have to think things through and be careful what you wish for because, as they say, you just might get it.