Everything thinks the crap they inherit is terrible. Everyone thinks they can rebuild it in a far better way. Everyone then passes their project on to someone else, who thinks the crap they inherit is terrible.
* Resistant to future change
* Won’t scale past x units
* Prone to operational issues
* Exposes us to liability or compliance risk
* Increases ongoing maintenance costs
Any large initiative to replace "crap" should map to specific product quality attributes that stakeholders and leadership buy in to, and ultimately be justifiable back to COGS or churn mitigation. In this way, objectively, a system can be $10M better because it e.g. closes $10M in customer tickets.