In this case, Anonymous will achieve making PayPal's website even slower for a while. If they lose customers it'll be for the wrong reasons. Anonymous needs to find a way to educate the public about a company's wrongdoings, not just disrupt the company's service while not making sure everyone knows exactly why that company's service has been disrupted. They seem to have this misguided idea that DDOS = public education and corporate humiliation. That's what I find shortsighted.
Anonymous has its own means and methods which you may or may not agree with.
If you agree that something needs to be done but think there is a better way to do it, then you need to carry it out, enough "armchair quarterback"-ing.
Maybe this isn't the way you'd like to go about it. It sure isn't what I had hoped for, but the fact of the matter is, it's time. This needs to happen. And if you hadn't noticed, in the age of the internet, sometimes you have to be loud to be heard.