When a good actor offers a terrible performance, it tends to be big news. All of a sudden, the Internet is awash with speculation as we all seek to find blame for this uncharacteristic drop in form from such usually dependable talent. It must be the director or the material or something obviously just wasn't right behind the scenes...There's always a reason, as fans try desperately to stop the one rotten apple ruining their entire CV.
And luckily for them, there does tend to be a lot of forgiveness out there for a rare miss - especially if they manage to get back on track with their next movie. After all, the world of bad movies is one built on quick-sand and not managing to get out straight away can be catastrophic.
That's why there are so many actors who seemingly make careers out of never actually being any good. They're there to take on the bad material so better talents don't have to, and most of the time they seem to know their lot. But then, every now and then these poor actors somehow manage to show flashes of uncharacteristic brilliance, shocking everyone who assumed they didn't have it in them.
And to be honest, that can end up being frustrating: because it's very clear that they've simply been squandering their potential in every other movie...