The segment and vehicles themselves are small enough that this changeover can be made fairly easily, with immense benefits for noise pollution in cities.
If you refer to e.g Asia where motorcycles are possibly your only transport, then sure; your argument is valid. But this is HN, and in Western countries a motorcycle is basically a hobby. Heck, they are often even more expensive to run than cars.
So as to why EV bikes are not even close to being ready:
(a) The range is abysmal, and the availability of charging simply isn't there in areas that many bikers venture (away from traffic, hundreds of miles into the hills). Motorcyclists try to avoid the interstate and main highways if possible. You rarely see a Zero bike for this and many other reasons. A proper ride may be 12 hours per day for hundreds of miles, for days on end.
(b) Battery mass. The energy per mass unit in even the best batteries make it very impractical with motorcycles that really need to be as light as possible.
(c) Longevity. A lot of bikers own not just one, but many motorcycles. You may have the latest BMW R1250GS, but also a garage littered with anything from KDX 200 to DRZ 400 and Honda CBR1000RR. Those bikes can still be used for years to come, and it doesn't make sense to scrap them. PS - bikes are generally not that reliable though, but that doesn't necessarily affect longevity too much as owners love to tinker.
That being said, I’ve only ever seen one EV motorcycle in China once (not just a big electric bike), it had unreal acceleration, I’m not sure it would be safe to ride.
But as (or if) the liquid fuel demand drops, you'll probably see the density of stations drop too. Both fewer pumps per station and fewer stations. But I suspect most areas will have some gasoline availability for at least my lifetime. Worst case, auto parts stores will carry 5 gallon jugs prefilled with stabilized gasoline. That would get a motorcycle around quite a bit.
For old-timers who hang onto their classic gasoline powered cars, they might need to plan trips around fueling stations, like natural gas drivers and EV drivers currently do. (EV is easier, you can always bring a 110V charger and wait a long time)
Electric motorcycles have been here for years, nobody is adopting them because nobody wants them. They are closer to electric bicycles than they are motorbikes.
When I jump on my motorcycle, it is about the experience - not anything practical. The startup ritual, the heat of the engine on a cool day, the symphony of sound and vibrations, the weight of what is under you, the absolute bliss you feel shifting through the curves of the road, the adrenaline of masterfully coordinating lean, angle of attack, rev matching, and counter steer.
There is something incredibly dull about an electric motorcycle comparatively. They are practical, and I will admit the linear acceleration is fun, but with so much sacrificed I could never see myself owning one as a recreational vehicle.
The loudest motorcycle this year when in motion? An electric motorcycle.
This obviously not including aftermarket exhausts.
Bikers keep their rides for decades and
ICE motorcycles can last just as long and cars, if not longer, and
The price for entry on a new electric motorcycle is so far away from the price of ICE motorcycles it financially can not work for owners. And
There is little benefit to the environment to switch. Modern motorcycles have been sold with catalytic converters for decades, and they also get 40+ MPG.
Previous emissions standards for motorcycles were much lower than cars. To the point where a bike getting 50mpg and carrying one person output more pollution than a sedan getting 25mpg and carrying an entire family.
This has been fixed with Euro4's introduction for the 2017 model year (which is why so many bikes were redesigned that year with huge exhausts.)
To automotive marketers this type of customer falls under "status seekers"
Around here, every cowboy with a V8 Challenger, Charger, Mustang, Camaro, or Pickup truck seems to have stripped off any semblance of "mufflers" because they want to "hear" their powerful V8 motor.
I live near a freeway entrance (and by "near" I mean at least 1/2 mile away), and out here, at night, when the freeways are more clear it's not too uncommon to have the silent darkness shattered by one of these cars opening up the throttle on the on ramp and racing to Vegas. Down the road is an interchange, and I've heard them start near me and just roar down the freeway, across the overpass and down the other freeway.
These cars are everywhere around here. Not to say the motorcycles aren't participants, but down here, the cars prevail.
Here's a 9 minute video that rebuts your 10 second unresearched, uninformed statement, with real data. Please watch it and become more informed about real ways we can improve motorcycles: https://www.youtube.com/watch?v=O2zlYpy6QCM