Yes, some people take Pokemon too seriously. Pokemon is a cartoon that should not be taken seriously. It does not make sense that people have elevated this cartoon to such a serious level. Pokemon is for kids and should not be discussed in the context of a memorial. Leave Pokemon to children.
Yes, there are people all around the world who take Pokemon Go far too seriously. However, the memorial to victims of the atom bomb explosion at Hiroshima is a place where people go to remember. The purpose of remembering is to honor the victims and to promote peace, because war losses are too costly. Therefore, the Hiroshima memorial should be kept free of distractions such as Pokemon Go.
Everyone enjoys a distraction from their busy, stress-filled lives, but many take Pokemon way to seriously, putting their safety and the safety of others in jeopardy. The game of Pokemon should be low on the list of player's priorities. They should not trespass or enter areas they otherwise would not go. The virtual game is frivolous. The Hiroshima memorial has a profound purpose and meaning.
It's silly to say that some take the Pokemon game too seriously when there used to be culture wars over chess competitions and people devote their lives to becoming grandmasters. Others spend their time making model trains or watching reality TV; why are those activities not mocked like Pokemon? It is true that Pokemon Go is a game played in the real world, so it is reasonable to ask the game developers to remove Pokemon and Pokestops from sites of historical tragedies (atom bomb memorials, concentration camps, 9/11 memorial, etc). However, the players do not determine the map or the spawn rate of Pokemon, so it is ridiculous to blame them for the appearance of Pokemon in those areas.