[saagarjha]

It's not permanently disabled, it enables itself when you are editing text (for example, if you're renaming a file).

[chrisseaton]

I think we're talking about copying-and-pasting files in this thread, rather than text in input boxes, as you're thinking.

[saagarjha]

No, I know that. I'm just providing insight as to why that menu item is there and when it enables itself.

[oneeyedpigeon]

I think they mean cut+paste to move a file.