Brazil is not ready to operate the Rio Olympics. The Olympic Village buildings are suffering electrical and plumbing problems and are not yet ready to accommodate athletes. The Zika virus is still an issue. The water to be used for sailing and rowing events is seriously polluted. There are not enough police to cope with the levels of mugging and violence.
It seems like pretty much everyone at this point agrees that the Rio Olympics are a disaster waiting to happen. Athletes have been robbed and a large portion of Russia's athletes have been prohibited from competing due to doping violations. Postpone them till next year and just host them in a country that is capable of running an event like the Olympics.
The Olympics in Rio should be cancelled because there are too many bad things happening there that could threaten the health and safety of the athletes who are not from that country. One should not go somewhere where they don't feel safe or secure. It is the host country's responsibility to make sure the athletes are being protected.
I do not believe the Rio Olympics should be cancelled, but athletes who do not wish to participate should be allowed to drop out if they so choose. There are numerous health and safety concerns, and attending should be at the discretion of each athlete. Zika is an ongoing issue, as are the inadequate living conditions and the water quality. Too much planning and money has been spent on the games to cancel them entirely, but people should be able to use their judgment without fear of mockery regarding whether or not they attend.