I think it's the bad kind of impressive, one where ATMs still run COBOL.
Programmers reinvent the universe every few years, but really nobody else does.
Besides, C is 44 years old and used on a ton of stuff.
It also doesn't look very trust-inspiring.
There were some high profile breaches at some retailers in the past couple years that exploited some 0days. How can you defend your POS/ATM against a 0day if the retailer/bank has bad network security practices?
Flaws are less important.
Most attacks are physically breaking into the cash safe but there were some attacks a couple years ago where people were plugging into the USB port and getting money or something.
ducks