Today's symbolic software is just software that was written by humans. Software existed as long as there are computers. AI was never just another term for software. I don't think any human written software today captures what proponents of symbolic AI wanted to achieve 50 to 60 years ago. Well, okay, it beat Kasparov at chess in 1996, but chess algorithms were old news even in 1970. I don't think Deep Blue used anything fundamentally new. It was not an AI breakthrough, it was a feat which showed how fast computers are.

The fact is, "AI" was always about much higher ambitions, about solving truly fuzzy tasks. Recognizing handwritten digits is exactly such a problem that has been solved, even if you don't want to call it "AI" anymore because it has stopped to be impressive.