There is nothing wrong with charity, but not everybody is going to be as deserving of it as they believe themselves to be. The internet has been a blessing of an invention for every single entitled person who wants others to have enough sympathy for them that they decide to give them money, but they are also at risk of being ridiculed by that very same audience. Not everybody is going to be willing to donate to a cause, no matter how worthy the fundraiser has decided it is.
It is true that you usually don't get if you don't ask, but sometimes it is important to weigh up the likely success rate of asking vs. the potential judgment that is going to come from it. Everybody has the possibility of falling on hard times, but that doesn't mean people automatically want to help them out. This isn't always down to pure meanness, either. They can see that what is being asked for is a little ridiculous, and not something that is worth engaging in. They want to know that if they are spending money on someone, they are doing it wisely.