Generally speaking, the more stretch goals, the less likely I am to back a Kickstarter. Especially when they have all sorts of stuff that goes beyond just designing and printing a book, like miniatures, a smartphone app, breakfast cereal, etc.
Without naming names, there's a currently running TTRPG KS whose first-day backer reward was early access to an app that's basically going to be a mobile-friendly social media platform specifically for that game and its players.
I couldn't click away fast enough.
Now, one sort of stretch goal I do like is when they have things like "this person will design a monster/magic item/thingie."
I totally forgot to mention how much I love this kind of community-building-and-reinforcing stretch goal.