Rockstar didn't have to create an entire studio from scratch.
It's obvious that you don't know much about this project. Otherwise, you'd know that "private investors" invested heavily in Star Citizen just a few months ago. Maybe you should have researched a bit before doing this.
That being said, considering the fact that trash articles like the one that sparked this thread exist, it's not surprising that some people talk about Star Citizen with zero actual knowledge of what it is about.
How much do you think Microsoft spent creating 343i and The Coalition from scratch? $100 million in just setting up a studio? $50 million?... $20 million...? Tell me how much it costs to bring in the talent and open an office building then we can decide how much Star Citizen has pissed away.
I've never argued once creating studios or creating games doesn't cost money, but to say that $300 million. THREE HUNDRED MILLION DOLLARS. The most spent on any game ever, with no viable retail product in site hasn't been misappropriated by those in charge is delirious.