I don’t think that logically follows.
I'm not sure what part you disagree with.
The structure and function of our body is determined by genes, and different people can have different variants of a gene, leading to slight differences in how the body functions. We see this in some obvious characteristics, such as how curly or thick our hair grows, or how our taste buds respond to certain flavors. But less obvious parts of the body can also exist in variant forms that may have little effect on their day-to-day function, but may be relevant to how we respond to disease-causing agents.
The coronavirus enters the human body through mucous membranes of the mouth or nose, penetrating the mucus till it reaches a cell which it can enter. Small differences in the thickness of the mucus, or what chemicals are in it, or how acidic it is might make a difference in whether the virus survives to infect us, or is rendered harmless. So it wouldn't be surprising if some people are genetically less likely to get infected.
Here's an article from Discover magazine that discusses the possible genetic basis for differences in susceptibility to infection.
https://www.discovermagazine.com/health/why-do-some-people-get-sick-all-the-time-while-others-stay-in-freakishly