I have never kickstarted an RPG either, I honestly lack confidence in most of the projects that have RPG tags, due to what others mention here, who is serious, who is grifting and who *thinks* they are serious. I have kickstarted a few campaigns by Reaper, and one for a board game (massive darkness). they all took a loooong time to get, well beyond target date, but I was at least confident the folks in the projects were competent at completion, if not punctuality.
I think that a lot of people vastly underestimate the amount of work, and level of discipline necessary to turn out a finished commercial product at a level that people would be willing to buy.
For instance: I run my groups Sunday Star Wars game with a homebrew rules set. But all I need to make that happen is a 15 page rules reference word document, a couple of xcel spreadsheets for my character sheets, and rules references for the players.
To try and turn that into a generic Sci-Fi RPG that people would be willing to pay money for? Pfffttt... I have a day job! The amount of time it would take for me to turn it into something that I would feel good about trying to sell for actual money is just not worth it. Hundreds of hours of work, never mind the upfront costs... forget it.
Something I have noticed about a whole bunch of people who fancy themselves in business or self employed...it seems to take some of them a loooong time to realize there is a massive difference in gross and profit, and that at the end of the day, profit is the only number that really matters.
This is generally because they do not properly evaluate their upfront costs, or the potential downstream issues and risks.
IMHO: a general rule of thumb is to add up all of the upfront expenses, add on an extra 50%, and then multiply that number by 3.
That will get you in the general ballpark of not losing your shirt.