Since Word 1.0.
Why do you think it is called Microsoft Office? The 1989 edition of Microsoft Word cost $500, equivalent to over $1,000 today, for a single seat. That's not consumer software.
Microsoft Home didn't exist until 1993, a decade into Office's life, when it had achieved complete enterprise dominance -- thanks largely to its competitors' failure to release Windows version in a timely fashion in the late 1980s & early 1990s -- and Microsoft began pushing into consumer software.
Some friendly fyi of MS history...
Microsoft didn't use the "Office" branding until 1995. Before that, the computer industry called it "productivity software" instead of "enterprise software". In the 1990s, other software companies (like Borland and IBM) were bundling word processors + spreadsheets + presentations + databases into an "office suite" for a lower package price.
In the 1980s, Microsoft Word was competing with WordStar and WordPerfect and those were all consumer software for personal computers. Consumers could go into an office supply store and buy shrinkwrapped boxes of those software titles. They didn't need a purchase order from corporate accounting to buy an "enterprise volume license". And consumer magazines like PC Magazine and PC World would run articles comparing MS Word to WordPerfect, etc.
Yes, a Fortune 500 corporation today can buy a enterprise volume licenses of MS Office (or Office 365 cloud subscription) but MS Word's roots definitely included the consumer sector. I don't think the example of MS Word fits the author's idea of "enterprise" software.
The shift was in computers, from enterprise to consumer, and the software followed.
A Dell all-in-one (not especially budget), is £580 [2]. A bulk buy for enterprise would be cheaper. This is inclusive of the cost of MS Windows OS.
In the UK a computer that can run MS Office decently costs around the price of the software.
You can see why MS create a new version every few years; but why do offices keep buying it.
[1] - https://products.office.com/en-gb/buy/office [2] - https://deals.dell.com/en-uk/productdetail/2sue
Maybe there should be another term to help clarify for people who don't understand the difference, but the difference really should be obvious from context.
That said, I do agree with GP that enterprise software is complex because it's designed to be adaptable to existing processes, whereas simpler software seeks to adapt the user to its prescribed process. And even without being an enterprise, I often find myself drawn to software that adapts to my needs and preferences rather than the other way around.
Just because the advent of mobile-focused product sensibility has seen a (regrettable, in my opinion) general drift toward significantly reduced feature sets in software does not mean that existing software with broad feature sets is now "enterprise."
Anecdotally, 20 years ago, scores of programs allowed the user to easily and broadly customize the colors of their user interface. That sort of flexibility was among the first features on the mobile simplification chopping block. As a result, most software created within the past few years has a single "true and good" color scheme dictated by the designer. Today we see that evolving slightly with the popularity of "dark" schemes, giving the user a choice between two, but only two, designer-crafted themes.