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.