Unity
requires (forced updates by unity, pushed to users) then a complete recompile of code if any changes of unity revision (which the forced update does have) no matter how slight of a change if you want to maintain currency in source game-app.
along with a need recompile to any mod or trainer to work again if any and when unity revision changes do happen.
video quality playback limits (to the unity version used in this game)
almost need a 4 year degree to deal with all the constant changes to unity versions and revisions on what and of how things are done behind the scenes.
cost nickle and dimes users to death from assets to (you want a certain video or file type to work with your project pay must for) plugins.
compiling time to end development of project, most use cases are much more steps and are more time intensive (when compared to renpy's development process).
renpy
Don't need to do a recompile at every renpy revision nor are you force to update.
Has a maintained universal mod
never had video quality limits, afaik
doesn't require exhaustive amount of knowledge to do small or large changes to source code.
most things are free or open source and if you can't find one to suite your needs you could always write one (a can't do in unity due to pay walled and propriety code at work).
I am sure there are plenty more comparisons both good and bad that can be made (majorly bad when compared) to renpy.
jm2c...
So that is primarily what your argument is about, that you can't mod the game to your liking? In case you aren't aware, there are cheats built into this game (as well as Faerin's other game, Mystwood Manor) that you can use at anytime throughout, should players choose to do so, eliminating the need for creating a mod. Mods have been known to cause more problems than they solve by
creating bugs in the saves. We've seen this time and time again, and every time we've ran into a save where a mod was used, they're immediately turned away. We can and do refuse to help players who have used mods and cheat engines in the past and will continue to do so because they are not supported by the developer nor has he given his blessing for people to create a mod for his games.
Your "Unity vs Ren'Py" complaint is an old and tiring debate we've seen countless times. Let's not rehash something all over again, just because you don't like the Unity engine (which is basically what this all boils down to). Faerin is not going to switch to Ren'Py anytime soon, if ever. If that's not to your liking, I suggest you play some of the other games you'll find which uses the game engine you prefer. There are more than enough on this site that should meet your needs.
Everything else you've mentioned is irrelevant. Ren'Py isn't as "great" as you make it out to be. Changes to the code or changes to the engine can and sometimes does affect players' saves where they would be forced to start over again. I've seen that with a number of games based on Ren'Py that I
used to play (and subsequently deleted) more than once. This seldom happens in Unity games unless there were major changes to the coding or UI. Considering I've worked directly with Faerin over his last 3 games (nearly 7-8 years now), I've only seen this happen three times. Once with MotH when I came on board, once with his last game and once with his new game which was very early on in development.
Now, with all that said, while I do enjoy games in both engines, to me, it doesn't matter, it's beside the point as I don't use mods in my games... never have as I don't see any need to do so. So I don't get all bent out of shape over a game engine because the game doesn't do what I want or have what I need. That's up to the dev. If they chose to add built-in cheats, great. If not, who cares? If they add hints in the game, that's awesome. If not, so what? At the end of the day, I'll either play the game or I won't. I don't care what engine it was built in.