Exactly as I have been saying. The areas of the body where Candida normally inhabits are naturally acidic. From your link:
"Much like other parts of the body, a woman’s vagina has a pH. A healthy vagina is slightly acidic, with a pH usually in the range of 3.5 to 4.5."
It is this acidity (pH below 7) formed by the natually occurring beneficial flora that keep the Candida under control. As the pH increases (goes more towards the alkaline side) the Candida growth gene is turned on and the Candida goes from a harmless yeast form to a highly aggressive and pathogenic fungal form.