well, collectors may feel threatened, but handcraft and technique researchers who make an enormous contribution to bead knowledge appreciate that the many skills of reproducing the old beads help us learn how they may have been made- even with "primitive" processes, what has been considered valuable/fashionable at different places and epochs in history, and so I do not look down on replicas but see them as tributes.
but i also seldom pay high prices for any beads so don't feel i'm taking a risk- and as you learn you can distinguish more characteristics.

having some fun rediscovering more bits and pieces as i go through and attempt to catalogue my collection... for future use.