1. That's fair, I didn't realize people were expecting my comment to be perfectly-aligned to every aspect of the thread parent, including the "their own hardware" part, but now I at least see where the confusion came from. For the record, any issues at this level of the stack are also present in IaaS, not just on-prem.

2. I still don't see where you got that they are only talking about configurations versus messing up an implementation (I.e. in a paramater they coded incorrectly)...

But that aside, even on AWS you're still configuring your proxies, gateways, load balancers, etc. AWS gives you just as much rope to hang yourself with as a box in a colo network cage does. Companies are already doing this stuff themselves, on-prem is not more security work. IaaS is about scaling and maintenance load, not security being handled for you.