Why are SQL injection attack prevention not implemented extensively?

SQL injection attack prevention is not extensively implemented due to a combination of factors, including a lack of awareness among developers about secure coding practices, time constraints that lead to shortcuts, and the prevalence of legacy systems that may not support modern security measures. Additionally, the complexity of applications can make it challenging to implement comprehensive security across all components. Budget constraints and the prioritization of features over security can also hinder the adoption of preventive measures.