This is the crux of the matter. This statement is not true. Times have changed and sport is no longer regarded as something that has to be athletic. It's why the ridiculous horse thing where they make horses dance is classed as a sport despite people thinking it isn't one, due to the (apparently) insane levels of coordination and skill it takes to get the horse to perform that way in tandem with the competitive aspect etc. It wasn't a PC reason that Chess was classed as a sport, it's because when you look at what elements constitute a sport, it exhibits them. Things like Mahjong are not not sports because it's Mahjong, that would be a ridiculously simplistic and naive way of looking at it but people do. The reason Mahjong is not a sport is because nobody plays it at a competitive level, it isn't ruled by a governing body etc. It's only played recreationally.
Sport is not a particular activity. Sport is the manner in which an activity is conducted. Football is not a sport when you play heads and volleys with your mates on the street, nor is golf a sport because I go to the driving range occasionally. Everything can be played as a game, as recreation, and can also be played in a competitive and sporting manner if done at a high enough level, meeting criteria that would deem it to be a sport. Some people find it difficult to accept that because it changes what they know and believe, but that's a local issue to that person.
It doesn't, there are additional criteria that these things do not hit.