While there's certainly some honest developers out there, indie crowdfunding has largely just become the 'Nigerian Prince' email scam for a younger age group. As others have said these people are just putting up a interesting project, do the absolute bare minimum to fool people into thinking you're still working on it, and then milk the suckers as long as you can. And the crowdfunding sites themselves are essentially in on it, because it's in their best interests to let it go without repercussions because they get their cut. Hell it's not even small time indie devs pulling this, Star Citizen has fleeced millions of dollars over ten years at this point to make little more than a pretty tech demo.
People might laugh at my reference, but it's same goddamn scam. Give us money and we'll finish this project, honest. Oh, I was sick this month please give me more money. Oops, it was too hard and I couldn't finish anything I promised last month; but here's one new room and NPC so please keep giving me money.