In terms of patrons* both Innocent Witches and Milfy City get blown out of the water by TiTS and CoC2, 3.7k-3.9k to 6.6k-6.7k, which have exceedingly minimal art and are almost completely just text. They also get beaten by Being a DIK (12.8k) Harem Hotel (5.4k), Hardcoded (5.1k), Cloud Meadow (4.4k) and various others I didn't recognize the names of or that don't mention the project names. And if this ranking/graph site is to be believed (And the other numbers all check out) they're also beaten by Monster Girl Island a game that last updated nearly two years ago and that is currently marked Abandoned here. ...I can't verify because their Patreon is also currently under review. I selected those games in particular because none include incest as far as I'm aware (At least, of the MC-is-related-to-someone variety.) I tried to get a smattering of different types of games.
Meanwhile, there are plenty of games with 3dcg, Incest, and Harem tags to go with
great reviews that get smoked by Seeds of Chaos. Mist at 675 (And I'll note a particularly low per-month-per-patrons. Average for SoC is $6.18, Mist makes $3.88 per patron.) The Awakening at 1,412. Waifu Academy at 1,377. Midlife Crisis at 495. My New Family at 1,181.
There are extenuating circumstances in some of those cases (Hello, Waifu Academy's update issues!) but the point is that it's a lot more complex than just "Seeds of Chaos has/lacks x." Sometimes it's the creator getting the word out or not, prior good will, other games of the genre before/after it launches, or seemingly just blind bloody luck. Along with various other factors.
If I had to pin two things above all others I'd say that SoC is dense as all getout in terms of lore and worldbuilding. Which
I certainly love, but there's a lot of people out there that seem to look for fire-and-forget porn and SoC certainly ain't that. And second, well.
it has an actual video game component to it that doesn't just hand you scenes.
This. There's a reason they reworked the old stat/skill system and Cla-min's shop. SoC had those old systems in it for almost the entirety of its lifespan thus far. And even reworked to be much better, some people still don't want that level of gameplay in their porn.
*Per-month money can't fully be gauged because some Patreons hide it. This can make a big difference because some projects engender a higher level of support among fewer supporters, but I used the only complete method I could.
**I'll also note as an addendum to this that going after niche markets can be absurdly lucrative. "Harem Incest" is about as non-niche as it gets in porn.