Would you care to re-read the post

(The current state of the post is very different from how it was when I originally downvoted it.)

Anyway. I downvoted "AI is Software" or whatever it was actually called at that point for the following reasons (all of which have already been mentioned by others here, I think):

• Main content was a grandiose claim with no real support offered for it.
  • Another way of looking at it: the central claim was (approximately) a deepity: you could be taken either as saying "let's redefine AI to mean all software" (not an exciting claim, merely a proposal to redefine a term; seems like a pretty stupid redefinition given the huge amount of pre-existing use of the term) or as saying "actually, with a proper understanding, all software is AI even with something closely resembling the prevailing definition" (a grand claim indeed, at least on its face, but also rather obviously false and with no evidence offered to outweigh its implausibility)
• What others have termed "pseudo-mystical" language with, again, no indication of why it's appropriate.
• A general sense that the reasoning (in so far as there was any) was muddled, and in particular
  • Little expectation that engaging with the author would lead to enlightenment on either side.
• Very preachy tone.

I have seen quite a lot of things written in that sort of way, and to date I don't think I have ever known any good to come from trying to engage their authors in a rational discussion.

I don't now remember for sure, but the following may also have been a reason and certainly would have been if I'd run across the article later:

• Author's extremely poor response to criticism: little actual engagement, much name-calling and taking-offence, and at some point completely rewriting the post without any acknowledgement of having done so.

The comments to this post contain further examples of this.