So.. you actually do. Otherwise the idea of an open minded leftist wouldn't be incomprehensible to you.
> Can you point to a single piece of evidence for the left being more open-minded?
Leftist philosophy has its roots in the French Revolution and the Renaissance, it and the left/right political axis wasn't invented on Tumblr. Traditionally, leftist belief tends to be the secular and progressive counterpart to the conservatism and religious ideology of the right, so by definition, the left tends to be open to new ideas, whereas the right wants to maintain the status quo.
The left was more open minded about secular science versus religion when the right was burning heretics.
The left was more open minded about the viability of models of government other than rule by the Church and a King. The Magna Carta, Declaration of the Rights of Man and US Constitution are all leftist in principle.
The left is more open minded about sexual identity, accepting LGBT culture and nonbinary gender identity, as opposed to the right.
The left is more open minded about race and gender roles, being the side that embraces civil rights and feminism, rather than the right.
The left is more open minded about sexual expression than the right, which still believes any sexual expression outside of monogamous, heterosexual marriage is immoral.
The left is more open minded about cultural and artistic expression than the right. The left writes most of the books that get burned and movies that get banned, because the left is the side constantly transgressing societal norms (which makes them more open minded about than the right in that regard.)
The hacker ethos[0] is entirely leftist, and I can't think of a more open minded philosophy. The right definitely would not have come up with something that threatened the gatekeepers and information brokers keeping Ma Bell, the big 3 tv networks and newspapers at the top of the information pyramid.
And here's something that will blow your mind - not every leftist agrees with cancel culture. Leftists are even more open minded about that than the right, which, like yourself, seems to see the left as some kind of SJW hivemind.