Re: One “benefit”
"Of Adobe’s subscription model is that it separates the straitjacketed pros, who are constrained what agencies, printers, and customers are willing to accept, from the less “serious” user, who can easily live with alternative solutions."
Only the "less serious user" could come up with such a foolish statement.
Of course one part of the puzzle is interoperability. But this is not the core reason why the "pros" remain with Adobe. For example, in the world of print, PDF rules the roost, so as long as you can provide the printer with a correctly prepared PDF, they will be happy (the clue is in the name "correctly prepared" though, most Open Source fanboy non-pros won't have a clue and so you'll annoy the printers because you've sent them a useless PDF, not because it is a PDF ... Adobe Acrobat happens to have lots of validation tools built in which is helpful in a pro workflow hence why most pros use Adobe instead of <alternative-pdf-writer> ).
However on the subject of interoperability, most pros will appreciate the lovely interop between the Adobe products. No need to waste time converting between random formats.
The real reason is the sheer maturity and quality of the Adobe tools. Competitors come and go with their half-hearted attempts at creating an Adobe-killer, but Adobe keeps on getting better. Real pros know that.
Finally, if you are employing a room full of 30 designers, the fact of the matter is most of them will have been using Adobe since they were old enough to pick up a Wacom stylus. Ask them to use <insert-name-of-so-called-Adobe-competitor-here> and not only will you loose productivity because they don't know their way around X, but also because X is less mature than Adobe, you will loose productivity because it will take the designers longer to achieve the same goal because X doesn't have half the functionality that Adobe does.