It's like a gambling game. You log in the account hoping that you are the lucky one whom this trouble has not affected. It depends on whether the luck changes.
You will be affected for sure even if the coins that are stolen aren't the coins you have in your account balance, because an exchange generally tends to socialize the losses.
In the end, this gambling you're referring to is what people do to themselves. No one is forcing you to leave your coin in your account just so you can sell quickly whenever the market sentiment shifts. That laziness is what makes people lose big time.
Just think about it, what do you rather lose, paper value, or actual coins? Loss in paper value can be compensated with time by recovering prices, but loss of actual coins doesn't compensate itself. You can only hope that the exchange will be profitable enough to compensate you at whatever point in time according to their own terms, which always favors the house and not you.
