I think one thing it can do is allow you to view things with fewer of the biases, assumptions and other mental stuff you've accumulated over the years. Having a fresh (childlike?) view of things can give you a newfound appreciation for many things (e.g. the environment).

> You know you're taking a drug that reliably induces feelings of "oceanic connectedness". Why should you change your worldview as a result?

Isn't that a little bit like saying that you shouldn't change your views after reading a book, if you are aware that the book commonly changes views?