I completely agree, and that's a huge topic unto itself.
Briefly, the issue with auditing, as with most things, is incentives over time. The difference between fraud in finance and software engineering is how long the bezzle[1] lasts. In finance, it can last a very long time in up economies, leaving Big Three auditors plenty of time to scurry off. In software you have to deliver at some point, leaving lying auditors exposed to discovery by security researchers immediately.
There is certainly still room for shenanigans if not set up correctly, but less than in finance.