Kind of a tangent, but I'll play along. To make your analogy remotely close, you need to add it the capability of you as the cyclist to harm/kill/damage the vehicle.....
So, pretend you had a James Bond bike w/ rocket launchers. Now when riding you have someone driving aggressively behind you. At the past 2 stoplights you can hear the ABS kick in, and the stop just short of you. It is clear that they are dangerous. Now an animal pops out ahead of you and you need to JAM on the breaks, but you know that the driver in the SUV behind you will drive right over you. Would you use the rocket launchers to save yourself from the actions of the SUV?
Yep, ridiculous as h@%*, but it was addressing your thinly applicable analogy. Bet you'd try to save yourself given 1) appearance that you could meet your maker 2) possibility to avoid that for today.
How about these:
If I am hiking and a grizzly charges me, would I kill it? Yep
If a bee stings me, will I swat it? Yep
If a water moccasin starts chasing me, will I shoot it? Yep
When I go running, if a dog hops the fence and chases me will I kick it? Yep
If a burglar enters my house, will I defend myself? Damn straight.
I've never killed a bear, have probably swatted bees, never killed a snake, haven't kicked a dog, and never shot an intruder. I believe I have EVERY right to hike in Yosemite, work in the garden, walk by my pond, jog in my neighborhood, or be in my house.
I've heard people express something like this 'you were in the wild, except the dangers'.... Yeah.... What, cause it wasn't 'natural' then I should accept all of the dangers and discount my ability to adapt? If you really believe that, please make sure to not buy a car with an airbag or antilock brakes, accept that your plane will crash, wear glasses, use modern medicine, ride a train ..... Part of being human is adapting to your environment. My environment is simply NOT a cubicle, expanses of concrete, or a condo.
The simple fact that you can't completely defend youself when on your bike has absolutely no bearing on what I can and cant do.
I simply won't go thru life with the believe that I can not and should not defend myself.