With the fee change, if you have a budget of, say, $15 to spend on creators on Patreon, it makes sense to split that into as few pledges as possible to minimize the number of times you pay the fees.

My guess is assuming this will change consumer behavior. Suppose bob sponsored 5 people at 1$ each before. Now if Bob gets charged a fee for each of the 5 contributions, he might change his election to 5$ to his single favorite creator, so that he is only charged 1 fee instead of 5.