To make things worse, this cannot easily be fixed because the implementation is a hodge-podge of ideas and functions. You cannot find good architecture people who want to work in PHP to clean it. It cannot easily be re-architected because it captures a lot of business wisdom. And business people (rightly) suspect pitches for a new built-from-scratch solution: sure, it will be fast and maybe it will be reliable; but will it solve their problem? will employees need to be re-trained? etc.