For every CoD, ActiBlizz release a Transformers.
For every Skyrim, Bethesda publish a Brink.
For every Gran Turismo, Sony bring out a Knack.
Destiny cost $140M to make, CoD Ghosts probably around $80M. You then have marketing costs on top (at least $20M for the big stuff), production costs, online stuff, and on-going DLC development costs. Sure, the real big stuff more than covers itself (think GTAV, costing a reported $265M and making $2000M, but that has to last over 4-5 years with the money it recoups!), but the non-AAA titles often fail to make a profit. That's why developers are closing studios and cutting back on staff, and we're getting more sequels and HD remasters than ever before.
Forza5 was a blip, everyone knows that MS paid T10 a fortune to give them a day one Xbone release title, which is why it was lacking in tracks. T10, to their credit, then carried on supporting it with cars and tracks long beyond the season pass limit. I have no grudges towards them for that as I feel I got my money's worth, but I do expect FM6 to be significantly better. GT7 I don't expect anything more from though with Polyphony, as they already seem to pack a lot of content in even if it is rehashed stuff. No doubt it'll look prettier though and have much more online racing options, something FM desperately lacks.