Encoding a decision table is the boring, easy, part, even if you do it in assembly. But that's not what the post is about. It's about the hard part, which is figuring out what the decisions should be. In many, many cases (most cases I would say), writing the code is the easiest, least interesting part of developing software.
But I totally agree! We shouldn't even write code for a decision table, because it's generic code which doesn't need to be adapted at all. Just use a decision table implementation off the shelf.
But I don't agree that encoding the decision table is boring and easy -- if the business logic is complex enough to require a spec. The good news is that now the table itself is all we need -- no self-written code, and no separate spec.