Many motorcycles (not bicycles, those are irrelevant to the comparison) already have more torque off the line than the available traction can handle, so that benefit from electric motors is less critical. The wear is a concern because motorcycles are already more sensitive to tire wear than cars, and simply switching to a harder compound to account for the extra weight has other ramifications that are far less severe in electric cars.
xkcd #2948: Electric vs Gas ( xkcd.com )
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