Because the consequences of him doing that are unclear. And since one potential (if not likely) consequence is management would simply retain 1/4 of staff doing this work and fire the rest, why would he share that?
Was there a huge sign at his workplace outlining the consequences of automating anything? An explicit policy that would alleviate such (reasonable - read the article!) fears? I don't think so either.
What was clear, presumably, is that as long as he processed X catalogs a day, he was getting his salary paid. That was what he was hired to do. And so that was exactly what he was doing.
>Why did he think it was OK to slack off for 6 hours a day instead of doing 4 times as many catalogs?
Because this is how work works. You pay someone to do something, and the expectations on the amount and kind of work - and the amount and kind of compensation - are discussed in advance.
>If this employee worked for me, I'd be putting him to work finding other things to automate!
Yes, and that's exactly the problem.
What if there aren't any? What if there are, but he doesn't find them? What if he finds them, but doesn't know how to automate the task? He was hired to go trough books and compare specs, automating his employer's business was literally not his job.
You see, your "reward" is not paying the employee 4X salary for being 4X efficient (you left that little part out!). Your reward is making the employee perform a more difficult job that they didn't sign up to do, presumably for the same salary (since you didn't mention paying them more).
Do you still wonder why they kept their silence?