For me there are so many plot issues that I don't really pay much attention. Eric is pretty clearly a bad guy based on his intentions, regardless what you think of Max. I also automatically imagine myself as the main character in any game where the protagonist is male. So that alone would make me against Eric even if he had some redeeming qualities.
Unfortunately, Max has no redeeming qualities himself as the main character other than having a big dick I guess. He also looks like he's about 12 years old to me, which makes things feel creepy.
Kira is porn star who is somehow obsessed with helping her nephew fuck her entire family. Alice is a cam whore. Ann is both comically gullible and strangely ambivalent about her son fucking her daughter while at the same time having a more normal resistance to incest for herself personally. Honestly, Lisa is the only family member with any redeeming qualities IMO.
I mostly started playing it because I thought the model used for Ann was incredibly hot.
Don't fully agree on the Eric part, but the rest I feel right there with you. It's a shame, if Max did not look like kid it might be more interesting. As it stands, I can't take any Max path seriously since he looks like a doofy kid and, to me at least, has literally no appeal.
Also not really into any of the other characters for the reasons you state. The aunt is boring, too easy, the mother seems legit drugged levels of out to lunch, and Alice is cheap.
I seem to be in the minority tho, as this is one of the more popular games. I don't get it tho.