it all comes down to size
Most companies are so monstrously large, they have no clue what is going on inside their computer systems, you only have to visit corporate websites to see that iceberg poking out. I once visited an ISP that had no access control systems in their building and was not challenged when I started wondering around. What is all of this saying?
Don't discount something because evidence is lacking, if you're not looking for it of course it doesnt exist.
Unfortuately we live in a world where appearances are more important than hard facts, after all, investors (sic), shareholders, and other such antisocial people only care about money and PR is king