You misunderstand what the word 'theory' means when applied to scientify theory. It means FACT - PROVEN FACT. It means sufficient evidence has been collect to accept something as fact. However, in the rare event that something can be disproven, there is something called falsifiablity.

What people casually say something is a theory, they mean that they have an ideaw about something.

So, absolutely no. It is 100% dangerous for people to thinkt hat a vaccination isn't necessary or that it's okay not to wear a mask in a time of a viral epidemic. The 'opinion' of someone who is not educated in the hard science of virology is not on the same levewl as someone who is. And their opinion can be dangerous.

To quote:

QUOTE: The scientific definition of a theory contrasts with the definition most people use in casual language. "The way that scientists use the word 'theory' is a little different than how it is commonly used in the lay public," said Jaime Tanner, a professor of biology at Emerson College in Boston. "Most people use the word 'theory' to mean an idea or hunch that someone has, but in science the word 'theory' refers to the way that we interpret facts."

https://www.livescience.com/21491-what-is-a-scientific-theory-definition-of-theory.html