I doubt that, it's more likely to be because a car hasn't seen you in their vision or inability on the rider's part to control their vehicle, turning too fast, countersteering, bad roads etc. Leathers are comparitively okay but bike helmets should be replaced if they have had any impact in an accident.
A motorbike needs more regular maintenance than a car something like 2 or 3 times more even taking into account most rider do the small-medium stuff themselves, that's a lot of Saturday afternoons. Motorcyle tyres are also more expensive than car tyres and last about half as long too, I think.
