ya the jury is in and out of leaving butter out on the table.
Whether you think it will go bad or not it WILL pick up the smells around it rendering the taste of it spunky. Even in the fridge.
They claim that even the plastic wrap that most sticks come wrapped in smells in the fridge will permeate into the butter. They claim that butter that comes wrapped in foil is the way to go to keep it 'fresh' and 'tasting' like fresh butter.
Me? It's a milk and fat product and it stays IN the fridge. I want my butter to be fresh bacteria free and taste like butter. :C