I never choose to stay logged in to anything. I log in when I use it and I log out when I stop using it. That used to be considered basic security. In a similar vein, I don't have payment methods remembered anywhere because I don't want to give anyone who gains access to my account free rein to go shopping with my money. That also used to be considered basic security. It annoys me that Amazon doesn't allow customers that choice and forces security-conscious customers to go into their account details and delete all remembered payment methods after every order.
Until recently, OcUK didn't require forum users to tick the "stay logged in box". It's an issue that pops up sometimes. This isn't the first time. In the past, it's been resolved in a few days.