You /could/ redo one without redoing the other. No problem. But the result would be poor. :-/

The console system doesn't provide a TTY, as in Unix, but instead uses a CGA/MDA text mode metaphor: a matrix of (character,colour) pairs. This leaves no information about the text that's been printed, per se - it's more like the text equivalent of a bitmap. No carriage returns, no tabs, just an arrangement of characters that happened to have been put in the right places. If you widen the screen, there's not much Windows can do except for leave the new area blank, because it has no idea at all which line breaks are significant and which were just wrapped. (And indeed, if you resize the buffer in the console window's properties, this blanking is exactly what it does.)

There's sort-of nothing wrong with this system, in that it makes sense for a certain style of text-mode GUI console program, that were at one point exceedingly popular in MS-DOS - but unfortunately, it's not so hot for the TTY style of console program that everybody uses these days :)

(Fingers crossed for a much-needed shakeup, but this nonsense has stuck around for so long - I don't think that console properties dialog has changed one pixel since Windows NT 4 - that it's probably a bit late now. Meanwhile, one solution might be to run cmd.exe with a better class of terminal emulator - emacs will do this.)