That last paragraph seems very important, huh? It is. It's the author's most forceful argument in defense of the Victorian philanthropists in the entire passage.
PASSAGE MAP
P1: Introduction of two criticisms on Victorian philanthropy and details of the first.
P2: Details of the second criticism
P3: A description of a view of people who criticize Victorian philanthropy
P4: An attack on that view
SCALE

So, in the final paragraph the author is attacking the critics of Victorian philanthropy. The author is basically saying in the last sentence that the Victorian philanthropists at least put their money where their mouth is; that the Victorian philanthropists were doing good in the world.