Part of that is due to the holidays, part of it is due to the tax year coming to a close since many donations are tax-deductible, and part of it is simply due to the natural reflection on how we’ve done for the year.
First of all, I think it is important to note that effective giving is work. Just like earning, saving, investing, paying taxes, and even spending, it takes work to do it well.
For many people, it’s all about the efficiency of the charity. They want to see as high a percentage as possible of their donation going directly to helping others.
There are times in life when it is easier or better for you to donate your time and other times when it is easier or better to donate your money. Obviously, you can do both in whatever combination works for you.