So as has been said there's near 400 people working on the game around the world. Your average software engineer may only take home $60,000 a year but in taxes, benefits, office space etc a $60k/yr dev costs over $100,000 a year (this is the case across all software development). So that's 4 million a year for the staff. You then have to pay tax, credit card/paypal fees etc on all revenue, so that's more that's eaten away from revenue. A lot of game asset artists are freelance, so their costs are pretty high (they've hired people who worked on Star Wars, Star Trek, The Matrix, Prometheus etc to work on art/assets so there's a lot of good talent working there, and that costs money. You have actors (both for animations and voice/face actors for the characters in the game, of which there are quite a lot) who also need paying for.
You then have infrastructure costs - even now there are thousands of games being played globally by the players, and petabytes of patches/game downloads to serve - all of that is costing money as well. Every developer needs development & test software, development machines of all different configs to test the game on which again are a cap expenditure. They're moving to a new sound engine - that is something they have licensed and will cost money.
The financial plan for Star Citizen is that it will release and continue to be expanded on and developed for for a long time - this includes continually creating and releasing new content and ships, new expansions etc (only single player expanded content will be charged for so all that online content won't be charged for). The game may not have cost 100 million to make by release, but they would be terrible planners if they planned to launch what is effectively a very large, no monthly subscription based MMO without enough money spare to be able to continue working on it, expanding it and running it for a considerable time - if they lacked the funds to continue maintaining it you end up in a situation where the game could become stale or even shut down within a year or two of release - it's good they have planned to be able to avoid that happening.
The reality is games (and software development in general) cost money to develop (a lot more than people outside of the professional software development world realise) - and it takes time to do. GTA V and several other large games have all cost well over $100,000,000 to make so it is not like Chris Roberts is over stating the cost of game development.
I wonder how they're doing it, and how easily it will be to stop it... I figured we really wouldn't see that much, since it's all managed from the server....