There's nothing really magical about algae. Dealing with algae, albeit frustrating at times, just takes knowledge and understanding. I've been following this forum for awhile, everyone here tries to provide knowledge and facilitate understanding.
Having been a fish keeper and planted tank enthusiast for years, dealing with algae is a part of life. The key is understanding. Algae is just a microscopic plant, think of it as a weed. Weeds get started because of available resources and opportunity. Resources tend to exist in nearly all media (soil, water etc...) Sometimes we add resources (fertilizer) for our plants. Other times we ignore them, such as in a rock garden or a pool. Opportunity is one of the best place to deal with them. If they never get started then you never have to deal with them. If they do get started, we beat them back vigorously and resume prevention.
This site's approach makes perfect sense, maintain proper sanitation (prevention) and they won't get a started. If they do, shock (beat it back). By doing this we can just ignore the resources.
My problem with addressing phosphates is twofold. First it suggests you're not maintaining proper prevention. Second, it ignores all the other nutrients (micro and macro) that plants need. When you create a nutrient deficiency you're begging for a weed infestation (assuming no prevention). Think about your lawn care, if your soil is out of balance you get give dandelions, clover, plantains, etc... the edge over your grass. Lastly we want some of those nutrients in the water. Some of us add CO2 and calcium to help manage our water chemistry. We all know plants (algae too) need CO2. (Calcium is a micro nutrient)
Are phosphates an issue? Short answer No, not if you maintain good sanitation (as stated above).