It comes down to three things:
1) the studies I've reviewed, which overwhelmingly support the strength of natural immunity
2) the adverse reactions that I've seen personally (I personally know more people that have had more severe reactions from the vaccine than I know who have had severe outcome from covid - purely anecdotal, but hard for me to ignore), and from VAERS (truly frightening), and
3) the very strange authoritarian approach the government and media have taken with this. I don't know of any vaccine or drug trial that would have survived the number of adverse effect that have been reported without being pulled. We keep seeing strange things like the CEO of Reuters being on the board of Pfizer as [1] mentions. But it's immediately flagged on HN. You can't even discuss it. Medical opinions from highly qualified doctors and health experts being silenced, accounts being canceled and removed from FB, Google, etc... frankly, it has me creeped out. I've never seen anything like it.
The "othering" of people who make informed choice about vaccination and decide against it is extraordinary. It's a global phenomenon. You can see it in some of the responses to my comment here on HN, even. Take a look at the downvotes for my comment - just for saying that my natural immunity seems to be robust. There don't seem to be many people willing to engage in an open and honest dialog about this, other opinions are silenced by any means available.
Maybe it's because I'm older and cranky, maybe it's because of a deep distrust of centralized authority, but the more someone pushes me to do something, anything really, the more I tend to resist.
When I couple that with the risk/reward evaluation and the advice of my doctor, all things things come together to make me decide not to do it.