Niantics made it clear from the beginning that they will not be releasing the game worldwide right from the start. They stated that the game will be released in stages but they also did announce that the game will be release in July.
Well, we are nearing the end of July now and so far, only a small number of countries have access to the app. The last country to get the app was Hong Kong and since then, we have not heard from Niantics yet.
Some people think that they might still be working on the server while other speculated that Niantics might be working out some deals with retailers like the deal they made with McDonalds in Japan and that is holding up the release.
Whatever the reason, the fans are worried that they will not be seeing the game this month. Hopefully the next release will be for a long list of countries or they will be hearing from more angry fans all over the world.