That's not the point of the article. He's not talking about writing a state-of-the-art spelling-and-grammar checker.
> And no, looking up individual words in some predefined dictionary doesn't qualify as half-decent spell checking,
Well, but the author is talking about that problem! Even if you don't consider that real spell-checking, his point still stands. Let's define crappy-spell-checking as "looking up individual words in some predefined dictionary"; that problem used to be hard and now it's very easy, as in, you could write one in 15 minutes using Python.
I read the point of the article to compare "spell-checking then (80s) and now", whereas others read it more along the lines of "looking up static English words then and now". Your nickname sounds japanese, but I assume you're talking about English as well, with those 15 minutes.
> And no, looking up individual words in some predefined dictionary doesn't qualify as half-decent spell checking,
Well, but the author is talking about that problem! Even if you don't consider that real spell-checking, his point still stands. Let's define crappy-spell-checking as "looking up individual words in some predefined dictionary"; that problem used to be hard and now it's very easy, as in, you could write one in 15 minutes using Python.