I think that's where I'm falling out on this discussion. You might be fine rinsing with tap water with no infection 99 times out of 100*. But the no-rinse StarSan is relatively cheap insurance, bumping it up to 9,999 out of 10,000*.
*These numbers are completely made up. Please don't quote them!
Agreed. There are a lot of variables happening here and you'd better believe that commercial operations are not taking this risk and are sanitizing or pasteurizing bottles.
At the end of the day you decide what level of risk you're willing to take and know that even 9,999 out of 10,000 is not 100%. Knowing your own particular risk helps you make better choices as to what you're willing to deal with.