It doesn't change the fact that $100 isn't the whole game, for long-time subscribers, the whole game will end up costing over $2,000...
It's way too expensive. Even $80 for the whole game is expensive.
There really needs to be a pinned post somewhere that explains what Patreon* is...
It's easy to just glance at it and say you're paying for a complete game, but that's really not the case. Patrons pay to support a dev while s/he is developing their game, and as a reward, they get access to updates as they are released, with higher-value supporters getting earlier access as part of an improved perks package.
If you just want to hand over cash as a one-off and get the game in return, you'll need to wait for it to be completed and buy it on Steam or somewhere, at which point it will be a price much lower than $100, I'm sure.
That's when you can compare it to buying a copy of Mario Kart or whatever, because until then, the two things being compared are not the same.
*other subscription models are also available