It seems to me that today's rationality is completely irrational in a sense that it attacks everything that is not rational. But who define what is rational? For example, many people like to back up their beliefs by scientific arguments or by pointing on the bad parts of religion. Yet in 19. century frenology was considered science. Today we call it pseudoscience. Is it lacking humility for most people or something else that they cannot accept that in 200 years people will laugh at our modern "science"?
And, if we are so deeply influenced by beliefs of our times why wouldnt relativism allow for more open minded approach in a sense that it would allow people to believe anything they want (without the need for justification) instead of using relativism primarily for attacking "old" beliefs (example would be the view that christianity is obsolete)?
Your comment seems to be in tension with itself. You end it by suggesting that we adopt a version of relativism "that...would allow people to believe anything they want (without the need for justification)." Yet you begin your comment by apparently condemning, as "completely irrational," the beliefs of those who think pseudoscience or religion are irrational. I don't think you can have it both ways: relativism for their judgments, objectivism for your own. You ask, "Who defines what is rational?" I take it you have some definition in mind when you describe critics of pseudoscience and religion as "completely irrational." Relativism has an undeserved reputation for being open-minded. Those who think that they can "believe anything they want (without the need for justification)" should feel no pressure to keep their minds open to any evidence or arguments against what they believe.