That seems like a total non sequitur. Do you also find the expression "like comparing apples to oranges" cringey, since apples and oranges are quite similar when compared to black holes?
I tried to avoid the "apple to oranges" objection you are raising by restricting the domain to that of "potential languages", which seems like the "fair" point of reference to take. Since Japanese and English are both natural human languages, I would consider comparing them more akin to comparing red apples and green apples.
The main point I was trying to make (which admittadly got berried at the end of my post) was that "wrong" and "not useful" are two very different concepts.
[0] This is best observed in deaf children who are not exposed to sign language at a young age.
The poster clearly wasn't making any broader claim about the "qualitative similarity of all human languages" (whatever that might be).
With regards to your link. Japanese absolutely has subjects.
The question of presisly what -ga marks is a bit more controversial, but calling it a subject marker is a perfectly defensible position. Indeed, having studied linguistics before studying Japanese, I found that thinking of -ga as a subject marker and -wa as a topic marker made the distinction easy for me.
The point of this comment is not to say that we should be teaching English-native Japanese students that Japanese does have subjects and -ga marks them. I am not qualified to make that judgement, and my benefit likely came as a result of leveraging my linguistic studies.
As others have pointed out, thinking of Japanese as analogous to English is counter-productive for most students. This is despite the fact that Japanese is analogous to English in most cases, including (potentially) cases where seeing the analogy could be counter productive.
Returning to the original article; this is a good indication that just because something is wrong does not mean that it is not useful. Anthropomorphizing might not be technically correct, but it could still be a useful tool to help our human brains make sense of the world or subject matter. In the same way that saying "Japanese does not have subjects" might not be technically correct, but it might still be useful.