I'm going to play devil's advocate here: OP is not wrong.
There is literally endless lists of single dev. indie games which have moved at light-speed compared to this game. Huge games, games that were dropped and picked back up, games with one dude doing everything. Its the nature of the indie dev. industry.
But to argue the point, I'll quote RimWorlds single dev. on his game.
“This game can expand endlessly. That’s it’s nature. It’s not a closed story like Portal 2. It’s an open system endlessly moddable, expandable. You can always play longer, more colonists, more wealth, more colonies, more mods, again and again and again. There’s always more to want. So faced with an endless treadmill of requests, I must draw the line somewhere. But where?
"Five years. I figure five years is a decent enough place. Five years are enough for $30. Five years are enough to call a game finished.
(Of course, it’s great to suggest new things beyond that, but to demand a developer work more than five years on one game for one sale is not, in my opinion, reasonable. In truth I think any dev who does two years has earned his keep; five years is getting into ridiculous territory. Not that I’m complaining of course; I’ve always liked working on RimWorld.)
“It won’t be perfect, of course. Nothing ever is. And I won’t even be finished with it. But – it’ll be finished.” -Tynan Sylvester
That guy is totally right. 5 years is getting crazy for any game. Half a decade. I'm going to be an ass and say that if you expect backers of this game to be patient at this point, you have a poor concept of time.
From what I can gather, this game looks like its been in dev. for 7-8 years. That -is- a long time. I think maybe Kenshi (Lo-Fi Games), UnReal World (Sami Maaranen, Erkka Lehmus) and Dwarf Fortress (Tarn Adams) are the only indie games that I know of that have been in dev. longer.
And two of those games the devs. came right out and said they would working on the game for the rest of their lives, and as of now have no intention of stopping. Kenshi is shooting from 1.0 relatively soon.
"When its ready" is not realistic in reference to Mr. Sylvesters quote, because it will never be ready. An artist is never "ready" to end a piece of work, but he can finish it.
My advice to the dev. is to decide on a date, take a break, come back and strap in and get it into -beta-. Then set a goal window for 1.0. At the current rate of patches, I'd assume 3 years. Or add on the purchase screen that you're pulling a Dwarf Fortress and will work on this game forever.
Great game. Good luck to the dev.