There is a fundamental point you seem to be missing: the failure of one engineered system does not invalidate the underlying technology. The Denver baggage handler was a dismal failure of design and engineering -- it does not mean that all automated systems will suffer the same fate.

Here's a classic example of spectacularly bad engineering, with a truly catastrophic result. Does this incredible failure invalidate all bridge designs? Of course not! In fact, after the collapse, they redesigned that bridge and it's stood for over 50 years.

Your argument is inherently technophobic, and it has no relevance. I'll say it again: the Denver failure was a failure in design and engineering, and has no relevance to the underlying technology.

And, by the way, if you want proof that automated, PRT-like systems can work, look at Morgantown: automated operation for over 30 years. And even though Morgantown is not true PRT, it's closer to PRT than Denver's baggage system.

See Wikipedia for links to the Morgantown system -- again, not true PRT, but neither is Denver's baggage system.