It is the way of the world, to the bigger series go the spoils and the cooler acronym.
GOW 1+2 have sold a combined total of 10.44 Million.
GoOW 1+2 have sold a combined total of 5.65 Million.
GOW has almost sold double what GoOW sold over two releases each.
So as the natural progression of things, just as MK now means Mario Kart instead of Mortal Kombat we must accept that GOW means Gears of War because when it comes to acronyms the size of the series does matter.
Tease.