No offence, but where have you been getting news on his perception in the last few years? He's proven probably the most significant philanthropist in history, this isn't new.
Let's say one of the most significant philanthropists. Carnegie and Rockefeller were extraordinary philanthropists and in inflation-adjusted dollars, Rockefeller gave away more.
What Gates has done that's unique is to pressure/induce other super-wealthy individuals to also donate their wealth to charity.
Gates isn't being measured as the most significant philanthropist because of how much money he is giving away, inflation adjusted or otherwise. He isn't even measured that way because he's also directing much of Warren Buffet's (and others) wealth towards philanthropy; those those are significant accomplishments.
Rather, he's being measured as the most significant philanthropist, because his underlying belief systems, is so all encompassing:
From: [1]
Guided by the belief that every life has equal value, the Bill & Melinda Gates Foundation works to help all people lead healthy, productive lives. In developing countries, it focuses on improving people’s health and giving them the chance to lift themselves out of hunger and extreme poverty. In the United States, it seeks to ensure that all people—especially those with the fewest resources—have access to the opportunities they need to succeed in school and life.
