Here's a few examples:
https://news.ycombinator.com/item?id=2457760
"arguably more bad than good being done"
https://news.ycombinator.com/item?id=2457760
"arguably more bad than good being done"
I don't think there is any substantial negativity associated with Gate's charity work. The closest you'll find is some in the educational space who don't agree with the metrics his foundation uses to measure progress.