Honestly, I can see why the dude in the OP is disappointed, but this kinda stuff happens ALL THE TIME in game development. Game Development is very, very difficult has many processes that are basically impossible to predict.
You're not really an 'investor' if you backed 20 bucks - You're a 'backer'. And if you use money to back someone, you're backing that person in good faith that that specific person will pull off what he's saying he'll be able to pull off, which is why people trust the old school creators more than some new studio that says this or that, simply because they have a proven track record. Publishers invest into TALENT, they don't necessarily invest into what the developer PITCHES initially, since the product might completely change through the course of its development. And the developer isn't really at fault for that, that's just part of the process.
So I can understand the disappointment, but that's just part of the deal, it's a risk you take and if you're unaware of that risk, it's really your own fault. I bet Activision was hoping for better Metacritics for Destiny when they poured 500 million bucks into the project, but even then you can never predict the outcome.
A lot of these kickstarters are kinda ridiculous if you have any idea about game development. You constantly see people asking for 50k or 100k to create games that'd take a professional studio with a proven track record 10-15m to make. If you pour your money into that kinda stuff just based on a bunch of concept art and a bunch of text a person wrote up... then yup, you probably didn't make a very wise investment.