"With A/B testing every site ends up being a porn site"
"A/B testing is for exploitation and dark patterns".
"You can lose money with testing, safer not to do it"

I don't know where these ideas come from, but there seems to be some ignorance around what A/B testing is for.

1. It's a measurement methodology. It is not prescriptive in what you can or cannot test.

The decision on *what* to test comes before testing (from research, ideation, etc). If you don't want porn or dark patterns on your site, don't test spammy stuff.

2. The alternative to testing is intuition. The idea that you can just guess what works is stupid.

A/B testing doesn't generate innovative ideas - that's for humans - it validates them. That's what testing is for - to validate business impact.

3. What if B doesn't work, and I lose money?

The alternative to A/B testing is not a harmless A, but a risky B.

Everything is constantly changing, it's inevitable. You will make changes, roll out new stuff. A/B testing makes changes safer for everyone.