Why leftwing?

Why is it de rigueur to be leftwing if you are: a poet, an artist, a dramatist, a folksinger, a popstar, a sculptor, a broadcaster, a novelist, an actor or indeed, somebody who is famous for being famous? Why speak with a single voice across such a wide array of contentious issues? - And one with a skewed world view at that?
Why so little originality of thought?

It is like an infectious disease.
Is it just a detachment from reality when you move in such exalted circles?

Most people who go through that leftie nest of vipers - often referred to as 'our higher education system' - manage to see through the nonsense when real life hits. (Naturally, this does not apply to those who are undertaking important bureaucratic and quangocratic posts for the government.)