You could get the government to pay a lot of money to make motorcycles unnecessary, but they already are.
Also $50 sounds high to me. Most standards are closer to $5-10.
If I had a motorcycle, giving it up would be the payment. Hence, I could pass the value on to someone else who assisted me, in theory.
If I "paid myself" I guess that would mean I could choose something else risky to do with my "balance" of micromorts.
A world where motorcycles act like curses is an interesting concept for a short story, but not very relevant to a discussion of micromorts.
* Not everyone is going to put the same value on their own life.
* Some people will find major restrictions worse than a very small risk of death.
There's three perfectly good explanations.
Also if you use $5 per micromort, a pretty standard number, you get a motorcycle-riding cost of about eleven dollars a day. Plenty of people would pay that on purpose.
Also using perpetuity math is really wrong unless you plan to live hundreds of years.
Also if you ride a supersports like the one you linked, you certainly won't be getting that $40k in perpetuity... :P
Therefore, someone out there should be willing to pay me to take one of these (I'd settle for $2.5M): https://www.ducati.com/ww/en/bikes/panigale/superleggera-v4
[1] 6 million riders, 5000 deaths per year