As another motorcyclist, I want to give my support to this view.

I have no desire to ride fast (I rather enjoy doing 40 mph on a park drive), but I need my bike to be able to go 100 mph so that when the person next to me going 55 mph starts to merge into my lane, I have the choice of slowing down or very rapidly accelerating out of danger. It's the same with cars. Having the "headroom" means you can speed up quickly in emergencies.

You don't go more than ~70 to execute that maneuver. By the time you've accelerated to +15mph more than your obstacle, you aren't near it anymore.

You're right, but the bike needs a max speed of something like 100 in order to hit 70 within a second or so. If 70 is the max, it will take forever to get there. Headroom. I never want to actually go 100, let alone 70.

Which is presumably part of the reason why the person who started this expressed surprised at the lack of a governor to limit the top speed rather than surprise at the lack of restrictions on total engine power.

Exactly. You need a bike that can accelerate quickly, not a bike that can do a massive top speed. Top speed has nothing to do with how quickly you can maneuver out of danger.