Rewrites definitely need skills and good processes. And most of all, they need support from all levels and the original team. For most things we of course have

Rewrites definitely need skills and good processes. And most of all, they need support from all levels and the original team. For most things we of course have the free markets for doing the culling: old things die completely and are replaced with new ones without any connection to the old ones. But some of these systems aren't in that world and cannot benefit from those processes.