An infantry feature could attract less hardcore sim gamers (like ArmA or Operation Flashpoint players). They could contribute to the battlefield in their own way, like real life, its way easier to fire a fire-and-forget infantry weapon or an M16 than having all the cool instruments of an attack helicpoter or even driving a tank.
This also could make more types of engagements i.e. small uraban infantry engalgements with APCs, cars, infantry and light survalliance helicopters (like Combat Mission games). In genarl many other possibilites will be available with adding some simple animations, the DCS graphics are not the state of art but they are very good, they give you a very clear idea of what they want to picture.
Thank you for your time :)