It might be time to recognize that Scriv and Linux are a failed experiment and start picking the path one wants most.
Is there anything positive you might say that would help someone who needs the functionality of Scrivener? As I said, my approach is not meant to be universal; it works for me, and anyone else needing an economical & practical solution.
The premise is two-fold: to take advantage of the current Scrivener offering, and to escape the insanity of the forced-march upgrade path. As far as writing and authoring (which is the primary focus of this entire website) there's been damned little "advantage" offered by hardware and software upgrades in recent years. My antique Dell 5000 with Pentium III CPU and maximum 512 Mb RAM, running Debian "Jessie" 8.3 and Scrivener for Linux, with light-weight Openbox DE, costs me exactly $0.00 and it very nicely does everything I need to produce internet-ready epub, html, and pdf-formatted books and articles.
And that's my point. For an individual focused on work production, and a stable platform, it just works, to quote a former innovator. Your "technical" points are very correct; it's just that many of us do not benefit from that rat race and some of us choose to jump ship. A self-contained software system, air-gapped from forced internet upgrades, serves the purpose.
It's a lot like the hysteria of the stock market crashes; if you don't sell the stock, you don't take a loss. Wait for a better day. Same with the housing market implosion. A house you're living in is just as useful for a residence whether it's appraised as "under water" or not; the catastrophe comes when you decide to sell. Same with current computer hardware and software: the financial punishment comes when you blindly follow the forced obsolescence path. I'm a contra rebel; I jumped off that path to nowhere a long time ago.