The problem I have with algae advice that says "this definitely causes that species of algae to grow/die" is that there are a hundred examples that support and a hundred examples that refute the statement. I strongly feel we should not say that we know 100% what causes a species of algae to grow or not grow without conducting proper trials and running the correct statistics on it. Without going through the proper steps we can't claim 100% knowledge of what causes a given algae. There will always be hundreds of counter examples and people who believe they know what causes it until we have solid well conducted experiments and numerical data to back it up. The best we can do until then is make educated guesses based on our personal experience which may or may not work for anyone else.
Whatever causes each species of algae to bloom can't be related simply to one factor, otherwise we'd have figured it out by now and never have algae issues.
My problem with blaming CO2 stability, fluctuations etc.. for BBA is that we cannot accurately, cheaply, or reliably measure CO2, or even measure how much BBA we have in a tank. This makes figuring out if CO2 is related or not very difficult at the hobbyist level.