Topic: Is it bad to leave a disk in the drive?

I leave the disc in the PS3 because if it is not being used it doesn't make any noise. I however never leave it in the wii u because even if you are not playing the game it is constantly whirling away and it is far noisier than the fan.

To some it is no big deal but I find it annoying.

My 360 harddrive won't open up in horizontal mode any more. But that's less of a always having a disc in and more orginal 360 gets dust in the disc drive like crazy.