That's basically what AA games are, and are sometimes somewhat successful...but usually not as successful as AAA games. Then you have the indie and solo developers flooding Steam with mostly low-quality games with a few gems...making it extremely difficult to get noticed. So not only do you need a game idea that is attractive to gamers (AAA games are established franchise with decades of releases and marketing), it also has to be implemented well (see the failures of this years CoD and Battlefield) AND you need a huge marketing budget to get your game in front of eyes (maybe you could get lucky going "viral") to stand out from everyone else.