A big sports event held once every four years is a pleasure for many people. In its long history the recent Olympics are controversial whether it is commercialised too much or not. Personally, I do not believe that the Olympics have become too commercialised for two reasons. 
First, International Olympic committee has a strict regulation regarding commercials. Its sponsor is limited to one company in one field. You cannot use the Olympics as an advertisement tool freely. 
Secondly, since the Olympics are run by our tax, it is a natural result to obey the greatest happiness of the greatest number. The power of mass media is strong and some people might accuse it as the proof of commercialisation. For example, the schedule of games is determined according to the prime time of major countries, but mass media response their receivers’ needs. The Olympics is important not only for athletes but also for viewers. Some children wish to compete in the future. Others like to see hard working participants. It encourages their everyday life. 
Finally, I do not believe that the Olympics have become too commercialised for the reasons stated above. I hope that the Olympics keep on promoting peace.