It's been like this forever and there's really no reason for it. If i copy or move files within windows, it's done in a fraction of the time it takes lightroom to do it. The only difference in having lightroom move the files is it also has to update the file location in the catalog. Which also should take a fraction of a second to do since we're only talking about 100-400 files at a time.
It's issues like this that make me consider using something instead of LR. It's litterally the most basic of tasks - would be a homework task in programing 101. And yet lightroom has always failed at this task.