I never bought her products to begin with. However, because the chemical sodium lauryl sulfate is so common in many, if not most, brand name products that contain cleaning agents, it would all boil down to price. I can understand why people would be upset that they were misled. Especially if the makers of the product claim otherwise.
Assuming the ingredients were dangerous either to people, my washing machine, or my clothes, I'd stop buying the product. Jessica Alba, however, would have little bearing on my decision. I would rather base my decision on the cold, hard facts and information than be swayed by a celebrity or their opinion on a product.
With so many different types of laundry detergent, I would do my research on the type that would fit my lifestyle, not the lifestyle of a celebrity. I would look into organic, types of scents, different brands and so forth. Jessica Alba is a celebrity and someone people look up to, but I wouldn't base my choice of laundry detergent on what she decides to use.
The discovery of certain ingredients in Jessica Alba's laundry detergent will not stop me from buying the product because I do not buy her laundry detergent, but also because there are lots of chemicals in most of the products I use anyway. Using green or organic household products is very expensive so sometimes I just accept that some product will have ingredients I wish were not in there.