Because I don't. I do see a lot of reasonable objections making headlines or having a large impact. E.g. side effects halting entire campaigns for weeks, or large articles highlighting the dowsides of various vaccines, debates on particle sizes and fluid dynamics on national TV and so on.
I'm looking for an educated answer, I'm not anti-vaxx, far from it, I'm just curious about it.
That time is however not zero.
Furthermore, you can carry the virus outside your body.
Also if you compare a population of 100 million people who mostly have that 20x protection with one that doesn't and infect one person the the end result is one or two infections in the first case and about 100 million in the second.
The ones who you could argue are at the lowest risk level – those that will have an asymptomatic infection and might not take precautions because they feel fine – are actually presenting the highest risk to every vulnerable person they encounter.