That's because her approach never resolved the issue. She didn't leave that situation feeling any better than when she entered it. The clerk was never eduacted on their clothes and why they're wearing them. Now that clerk will just go home and tell her friends that some crazy woman screamed at her during work. The hate will spread even further. The mother just uploaded the video to make her pop off feel more validated by the internet. This only leads to temporary fulfillment and she will just get angry at another situation later on.
This is on a individual basis and all of you are including the collective. Some of you blinded by hate and anger saying the mother has every right to go off on the clerk because she is a bigot. Your solution and hers is to just expose a racist to make yourself feel good. Then you will just move on to the next video that pops up. These solutions don't end racism. One day you will learn to actually talk to people and resolve issues instead of looking for internet approval of your actions or others.
It's funny that you would post this in a thread of over 650 posts discussing the mother's actions. Not every post has been good but there are a lot of excellent posts in this thread. It's almost like talking, right now! I feel that some people have learned things. And that's just in this one thread on this one forum, and doesn't take into account the many thousand sets of eyes who have checked out the thread without saying anything. This is a discussion we wouldn't be having if Ms. Mabilijengo hadn't stood up for her children and her culture and shared it on the internet. And this discussion has value.
She can't win with everybody and I think she probably knew that. The cost of forcefully standing up to racism is that some will recoil from it. The fault in your argument is your lack of critical examination of desirable, realistic results...of what her goals might be here. "End racism" is not a realistic goal in this scenario. A better goal, one she is more likely to have considered, might be "show my children they do not have to put up with casual racism ever." Or "show Sandra the consequences of casual racism towards customers in this community." And so on. It's silly to expect more from her.
You're also making a lot of assumptions about what Sandra does after this is over which I don't think is really worth responding to. This, though:
This only leads to temporary fulfillment and she will just get angry at another situation later on.
No shit? Her website and blog make it abundantly clear that Ms. Mabilijengo is a tireless champion who will never, ever let casual racism slide. Good for her.