No idea, I dont get why theres no ctrl-copy, ctrl-cut and ctrl-paste, no alt-f4, no ctrl-alt-delete, no ctrl-z and ctrl-y, no ctrl-a, ctrl-s, ctrl-o, no mouse-hover-menu-system for IE10, etcetera.
I guess its mostly because... you just do things slightly more cumbersome since its touchbased instead of full QWERTY. You mark the first/last word, and drag the marker to the end/start of the text you desire to copy, and thats that.
Mark->select. Its no harder than mark->longpress->copy compared to mark->ctrl-c, but thats the trade-off when you want a pure touch device. It seems.