First off it was 80 million
Second, did you play Peace Walker? Same exact structure as MGSV. No one makes a story with only 2 chapters. I won't say there was going to absolutely be 5, but you don't start a story with a Prologue, Ch1 and end it on Ch2 (1/2 a chapter). There is evidence that there was more missions and a chapter 3. And usually when someone throws a prologue, you get an epilogue. To think we are crazy when the evidence and common sense proves otherwise is you want to focus on your emotions. It's cool we all are but not all of us are just shouting for the sake of some fantasy.
Also some of that 80 million went to the creation of the Fox Engine which in tern would have been a great investment considering it would have saved them money on developing other Konami titles like PES, Silent Hills, and possibly a new Castlevania.
Let's not forget, this is the first multi platform MGS game that launched simultaneously giving it a far better chance of making the money back. I think in an earlier post someone said the PS3 only MGS4 costed 70 million. But Konami in all its wisdom decided it was better to save money by throwing away money. Who knows maybe it will work with sell phones.
Either way we got the game we got, and Kojima spent them obey he spent, but we aren't crazy for believing the game had more content, when content in the trailers that didn't make it in the game, leaks of actual cut content surface, as well as standard story structure tell us otherwise. The game was cut plain and simple, don't let Konami's forced Sept 1 release date make you believe that was when the game was supposed to come out.
Hideo Kojima quote from IGN
http://www.ign.com/articles/2014/03/05/kojima-worried-the-phantom-pain-is-too-big-to-finish