Why should soccer be called football in the United States? Well I don't think it should. The debate over the use of the word soccer to describe the world game is one that is not isolated to the Unites States. We have had the same problem here in Australia.
If we want to get technical, both of the names, soccer and football are incorrect. The proper name of the sport is association football.
The name football is a generic term used to describe any ball sport that is played on foot, as opposed to horseback. It has nothing to do with the act of kicking the ball as many people believe.
Association football is one of many versions of football that were developed in England around the 19th century. The other major code that has stood the test of time is rugby football, famously started when a student by the name of William Ellis picked up the ball and ran with it.
In true English tradition, the names of these two sports were quickly shortened to rugger and asoccer later shortened further to simply soccer. Both of these terms are still widely used today.
One trend that has grown over the years though is for the most popular ball game of any given area being dubbed simply football by the general population. In most of Europe, South America, Asia and Africa, this is applied to soccer. In the United States the term football is used on what the rest of the world knows as gridiron. In Australia, Australian rules football is the generally accepted game identified as football, though this is not the case in the northern states of Australia where rugby league is dubbed football.
So, is it really necessary for the United States or Australia to call soccer football? Personally, I don't think so. As long as the majority of people know what you are talking about then I don't think a widespread change in terminology is warranted.
In Australia we have four major codes of football Australian rules, rugby league, rugby union and soccer. I use the term soccer simply because I would need to further clarify what I was talking about if I merely called it football. With that, I also refer to each of the other codes by their proper name too.
Until you can walk into a bar in Dallas and ask someone to talk about the football and they immediately speak of David Beckham at the LA Galaxy or the chances of the USA qualifying for the World Cup, and not the fortunes of the Cowboys, then it is unrealistic to expect the name soccer to be removed entirely. Sure, the rest of the world's population call it football, but it is not a term built into the fabric of American sports fans, so why try to force change?
I don't understand why anyone would actually care what the game is called, surely the most important thing is getting people to watch, play and support the game. As Shakespeare said a rose by any other name!