Spirit and Opportunity were launched in 2003. Camera tech was suffiently far along to make this sort of imagery. Look at Cassini launched in 1997. Perhaps it would cost more at the time but this is a cost that I think would have been necessary to bring back images that could stun and awe the public into addressing the space program into having incredible benefits to giving us the perspective of understanding what's out there and our place in a what seems to be a vast desert.
Cassini and Curiously have finally done that.