Audience taste would largely adjust. And if they want unsafe sex, screw them.
If people started demanding that car races ban helmets and safety gear because people enjoy the excitement of more danger, should do they do that too?
How about demanding trapeze artists not have nets? Real bullets in action movies?
There's this thing, it's called the free market. When you ban something that people want, the market will provide it to them.
Require condoms in American porn? Condomless porn will be produced elsewhere. I know I'm certainly not watching porn with condoms in it. This same argument has been raging with gay porn for a while, and people like you have been throwing a fit because gay barebacking porn has been increasing exponentially. People don't like condom porn, it ruins the fantasy. They will seek out condomless porn.
And there are absolutely shows where the trapeze artists don't do nets. How old are you? Do you never remember going to the circus and them saying, "And tonight's show will be performed with NO NET, with a 200 foot fall between the performer and the ground!" Personally I don't care about that one way or another.
But I'm not watching straight, gay, or any other porn with condoms in it.