No, we can't afford to do this on our own, not on anything approaching the timescale I've outlined. That's the whole point. If I already had these funds in addition to what capital we have, I would not be asking for it, period. One way or the other, we *are* risking our own capital, these funds are only enough to close the gap to make the near-term timeframe realistic.
If you could write a book over a length of 20 years, does that make it morally questionable for you to offer a Kickstarter allowing you to write the book in one year? What about if it would take you 5 years on your own? A big part of the point of Kickstarter is about reaching a critical mass that allows something creative to come to fruition.
There is a similar critical mass to a major game expansion on a complex MMO title. All this does is give our 4-person company the resources to focus purely on development for enough time to make this happen cohesively. If we did it without additional support it would probably take us several more years.