There are limits (in their ToS) to the amount of ads you can have on a page, and this was way beyond that limit.

I’ve made this mistake myself :)

“Fixing it” here just means removing some of the ads. I suspect he’ll actually make more money after removing most of the ads.

Thanks.

I suppose the "more money" is that you would expect more conversions as people spend longer on the site and less time clicking away from the ads?

Correct