When a software is started building from the scratch or with basic options and focus towards a specific ideas of a client; we are working on client’s satisfaction. Rather than the whole system we are prioritizing the important business functions first and never sat back to redo when necessary.
100% mapping with business functions and good end user experience is mandatory on the fundamental software engineering principles. Via Object Oriented Software Programming(OOP) we can map the software system fully with the physical system.
What you seed is that get sprout. Never a jack fruit from a durian seed. Missed security focus in early stage of the designing, effect the outcome product that is hackable latter on.
Nothing new to to invent from mighty hours of thinking. There are security guidelines for various platforms. For example if you follow OWASP security guidelines lots of adversary attempts can be mitigated from web applications.
More, when the system is modeled from the business procedures and policies (Rather than just supporting business functions) security measures can be enforced to strengthen business integrity and ensure robustness.