the spores don't develop until the bubble gets larger, so you can pop the small bubble without release spores. Also smaller bubbles contain less spores than larger one do. Yes things that eat them will pop them but they will also eat the newly formed ones too. With a combination of these two things, eating the bubbles and the spores either not develop or not a lot yet, eventually your tank will be free of them.
What does help is to have really good water moment in the tank, that way the spores can't settle down and most will get sucker up in the over flows. You do need to look in the over flows as you would be surprised how many are in there. I've seen tanks that have crazy flow with no bubble algae in the main tank but the over flows and sump where filled with them.