I remember when humble, funny Justin Lee Collins was exposed as a vicious abuser. It was like finding out that Barack Obama was grabbing women by the pussy - it turned the world upside down.
But since then I've read and heard of sooo many beloved comedy performers who are arrogant, rude, dicks to their wives etc.
It's acting, all of it is acting. You see the self deprecating, witty guy on TV or on stage and because he performs under his own name you think it's him. But he's worked for years on his stage persona.
Watson has been a selfish knob, no doubt. Can't say I'm more or less likely to read his book based on that though, there wouldn't be much culture left if we shunned artists for infidelity.
Nadia Sawalha referred to her sister Julia's ex, the adorable curly headed Alan Davies, as a 'cunt'. I believe big sisters.