Because a large number of ppl (of all religions) only pick and choose the pieces of their "faith" that they choose to follow. Also, in America esp., we are desperate for attention and external validation because we have not learned how to find validation internally.
They would be modern day Pharisees. One reason I like the fact that at my church you can give online. I don't like everyone seeing what I do. It's private and between me and God. And if I help someone out that is between me and them. If they want to give a shout out, that's their prerogative. Otherwise, Im not telling anyone. :)
It makes me sad as well. I can say I have been on the recieving end of anonymous giving, and it is more of a blessing to me not knowing. I often feel ashamed of our need, and while i want to share my grattitude, I feel akward in relationships with people who I know have given me money. When I've been able to give, I try to make it anonymous as well. The joy is exponentially greater.