Regarding the certificate, the way I see it is not a person that has to show why he or she's against, but rather the Govt to tell us on WHY it's justified. So I'm the one who actually has to prove on why I don't want to show details of my personal life to do mundane tasks like having a dinner? No.
I see that justification was mainly based on two things, that personally I would be flexible enough to concede, but they don't prove to be 100% true:
1. To reduce spreading of the disease by the infected people. Not only we have contradicting studies, some of them showing us that spread rate is not quite different from vaccinated to unvacccinated people (
https://publichealth.jhu.edu/2021/new-data-on-covid-19-transmission-by-vaccinated-individuals), but we also already gave the chance to everyone to vaccinate and protect themselves to virtually 0% chance of dying from it;
2. To "convince" unvaccinated people to vaccinate. Most of the people I know that are not vaccinated are conspiracy theorists that actually use the passport argument to prove that this is an all out Govt scheme to kill us or whatever. So it actually has the opposite effect.
One thing is my personal stance, another thing is to which point I am flexible enough to compromise. None of those 2 points where I am flexible enough to compromise happen to be 100% factual, so I don't.
My personal stance is actually harder. I don't like having to show passports to enter a restaurante or a bowling alley. I like to keep Govt out of our lives, and "passports" and other things like that smell fishy as hell to me. Personally I will gladly take the risk of myself to increase the chance of dying from Corona from 0.1% to 0.3% or whatever (given that we're vaccinated) in order to keep Govt hands out of people's personal life. I would say the same if I was 80 years old.
Our Govt is actually removing passports from daily life in Oct 1. Gladly.