Text originally in written one script has often been published in another related script because:
a) in the age of metal type there was no widespread availability of fonts for many scripts and it was very time consuming and expensive to create them. b) there may already be a large community of scholars who read one script but not the other. If you are publishing a book your going to have a wider audience if readers don't have to learn a new script. These kinds of circumstance may mean that a kind of "unification of convenience" has occurred at least among at least a group of scholars. If you are used to this, then it is only natural to see the two scripts as interchangeable. However is the fact that a community of scholars has been used to writing and reading text of one script in another a good and sufficient reason for unifying them in the UCS? The technological limitations (lack or expense of fonts) no longer apply. And because some people use two scripts interchangeably does it mean that others should not have a choice? Once we get beyond the BMP space limitations are no longer a compelling argument for unification either. - Chris
