Use of a comma to separate a single word

Question

I brushed up on the use of Japanese commas (読点) here, but I don't think it explained this usage I found on 知恵袋.

The sentence is this:

忙しい、の対義語に当たる形容詞は何でしょうか。

Why exactly is the OP using the comma like this? The rule of thumb for me in English is that if you pause when speaking, you should use a comma in writing. I've just carried that over to Japanese somewhat, but this sentence would sound very unnatural to my (non-native) ears if one where to pause after 忙しい. Is that just not the case? Is this a standard use of the 読点 or internet slang, or...?

Answer 1

Strictly speaking, I think it should be

「忙しい」の対義語に当たる形容詞は何でしょうか。

but the person wrote it as

忙しい、の対義語に当たる形容詞は何でしょうか。

probably because s/he thought it wouldn't cause any confusion (and maybe because s/he was just being lazy; I might do that too when I want to save the trouble of typing the brackets :p). If it was like

味でなく、考え方などについていうときの「甘い」の対義語に当たる形容詞は何でしょうか。

then...

味でなく、考え方などについていうときの(、)甘い、の対義語に当たる形容詞は何でしょうか。

might look a bit confusing and it might be a bit harder to realize how it's parsed at first glance.