Stop showing giveaways for games already won

I noticed that once you win a game, the system removes all your remaining entries for it automatically. And that's awesome. But I won a couple of popular games (given away often) and I had to manually filter them out in the settings because they would simply become clutter. I mean, you're not supposed to win more than one copy of a game, so what's the purpose of seeing their giveaways after you've won? Couldn't they just get automatically added to your filter list with a possibility to be removed, if we really want to leave that option to the user?