Most software today is over-complicated, and riddled with vulnerabilities. Over-engineered software is more likely to have vulnerabilities but companies have embraced 'security through obscurity through complexity' anyway because complexity makes vulnerabilities harder (for humans) to find. AI could automate that.
I hope it will force a return to well-designed, minimalist software instead of the current 'security through obscurity spaghetti code' practices we have today.
On the development front, it might also be a positive. Any noob developer can produce ugly spaghetti code which barely just works, and now AI can do it too! What AI cannot produce is simple, human-readable code which can anticipate changes in business requirements; this requires business domain knowledge and common sense.