Also it cost a lot of money to make and approve dlc so even if the dlc sold better then the game it may not be cost effective to make more.
You don't know how much money it costs to make or approve dlc. You have no idea what the cost benefit ratio of creating new dlc would be or even what the breakeven point is.
I don't know either, but I do know that if the dlc sold better than the game of course it would be cost effective to make more. If it wouldn't, why would they have ever made it at all?
Do you know what costs the most money? Selling nothing. That's what they're doing right now.
But whatever, I'm assuming that someone from WB took a look at the MK9 sales numbers and ordered NRS to immediately begin work on MK10.
I really couldn't care less if they release more dlc for MK9. I personally think the cast is already too large anyway for such a deep game. There may be a handful out there, but I doubt there are very many people that regularly use each fighter.
The only reason I care is because during MK9's development, Boon constantly talked about dlc and said this game was being made with dlc in mind. I know he said that how much dlc is released is going to depend on how successful it is. Well, it's been hugely successful, and no additional dlc has been released, so obviously he was either lying or didn't know what he was talking about.
I don't know why I would have ever expected more from the MK team. The lesson is to just not buy into the hype and take everything you hear from NRS with a big grain of salt. With how many times they have been wrong and/or lied in the past, I don't even necessarily believe him that there is no more dlc.
My biggest hope is that the team is working on a sequel that will actually be good and not listening to a bunch of people who thought MK Trilogy was a good game. The last thing we need is a sequel with things like brutalities or Motaro in it.