Not gonna lie, I never even noticed there were ads. They all seem to be links to other Addons by that creator.
If all ads were that unobtrusive and related to the content I probably wouldn’t even feel the need to use an ad blocker.
It’s not like this is unheard of for Addon creators anyway. A link to the website, or a “See our other projects” link is perfectly normal for Addons/open source software. I think you’re blowing this out of proportion.