That's not really the case though. Even at the lowest tier you get access to the game right away from DC's own servers and you'll be able access the stream archive which basically includes every stream ever recorded by DC. I'd actually argue that everything above the $1 tier is pretty optional.
Next to that it's certainly true that people who pay very little will care less and may even still be happy to support - after all, it's just $12 a year.
He actually quit his day job before he started working on SS. Back then he left the animation industry to start freelancing and SS was actually supposed to be his personal coding excercise to teach himself how to work with renpy. As mentioned many times, this game was never supposed to become anything at all, let alone anything big, which is why so much has to be reworked now in the first place.