You can't find a extra $100 to donate?
I think people are being a bit insensitive. There are, sadly, plenty of people in our society who do NOT have an extra $100 lying around for any purpose -- making donations to University athletic funds or any other.
In fact, there was an article in Forbes magazine earlier this year that stated that, based on a survey conducted by bankrate.com, 63% of American adults do not have $500 saved for an emergency expenditure (e.g. unexpected car repair). Another study conducted by the Pew Charitable Trusts in November, 2015, reported that 33% of Americans have not even $1 of extra money. (Link to aforementioned article:
63% Of Americans Don't Have Enough Savings To Cover A $500 Emergency) Contrary to what some report, our economy has still never completely recovered from the economic crisis of 2008-09. I personally know people who had full-time steady career jobs at that time who are still just making ends meet with part-time, seasonal and temporary jobs far below the type of job they had before, and others who are still in the same job they had then with no promotion in the intervening years. (NB Your author himself is what most would consider "underemployed," working in a clerical job despite having multiple degrees, but very happy to have a full-time permanent job with benefits.)
My point is that perhaps we could be a little less hard on people who say that they don't have the money to donate to the athletic development fund, given the current continuing economic anxiety in our country. Just because you have the wherewithal to do that doesn't mean that everyone or even most people do.