The website is full of tracking stuff (has both Tag Manager and Analytics) and has Google ads. So I am guessing what they mean is, we will not be able to know everything about you and advertise to you if you don't disable AdBlocker.
This is a great site, and I really like what they are doing and going towards. I just don't like how it's littered with Google trackers, etc.
I hate ads just as much as everyone else, but if that's how they are planning to pay for hosting/time, it is absolutely needed.
You can do lots of things.
If nothing then perhaps it was needed.