Harry Potter is very flawed and all, but it was completed in a reasonable timeframe. One year for the first four books, then 3 years for the largest one and two years for the final ones.
Book 1 97
Book 2 98
Book 3 99
Book 4 00
Book 5 03 (Pregnancy and Warner Bros)
Book 6 05
Book 7 07
Imagine Rowling pulling a Martin and simply not finishing SoIaF. We'd be a book 5 and waiting decades for book 6 and 7, which aren't worked on anymore and at best will be adopted by other writers once Martin dies.
Obviously you can't equalize books written by a single author with videogames done by a few people, but its very clear that SoC development is flawed. 9 Years and we are still finishing up part 1 of 3, with no indication what could happen in the next parts.
So your problem is entirely based on some arbitrary end point for the story. So because SoC hasn't hit this arbitrary end point it is flawed because some other creator in another medium reached their arbitrary endpoint sooner?
The development timeline is quite long, no doubt. But at this point I imagine the problem is the double edged sword that is Patreon. In order to keep their Patrons happy, they probably need to pump out X amount of smut consistently to keep them paying. This would be like racking up a huge pile of credit card debt and then only paying the bare minimum; 5 years later and you're devoting a sizeable chunk of your spendable income just to maintain the debt without even touching the principle in a way that actually diminishes it (e.g. 30 year mortgages are outlawed in most first world nations outside of the US for this very reason). So I can imagine them finding themselves needing to pump out more content, even if that content largely fills things out and eats up most of their time and resources, leaving little at the end of each month to dedicate to pushing things ahead.
Had J.K. Rowling made her living paycheck-to-paycheck off of her Wizarding World work by posting short stories per month, she could have very well also found herself in a position where she was constantly filling in tangents and following up with interesting side characters if doing so is what kept her audience happy and the lights on; progress on the overarching story be damned. So are they 'milking' their Patrons, or are they being backed into a corner by them? I dunno. But given their nearly decade long track record of delivering solid engaging content (again, main overarching story be damned), I am comfortable in saying they aren't scam artists.
Serialized content doesn't need to be your thing, but it's not necessarily a mark against the game or the quality of its current content just because it hasn't reached a (once again) arbitrary self-imposed end point. You're looking at a team slowly treading water successfully and bemoaning that they haven't finished their self imposed race, entirely oblivious to the idea that failing to tread water as a swimmer means
you drown.
It also completely misses that the point of the post where you quoted this from; where I was using popular YA literature as an example to lambast someone who was trying to move the goal post and argue the game fell into their subjective definition of 'bad' because being solid or competent wasn't good enough for their taste.