Because adblockers can (and do) block all scripts and sites that mine without consent. Specific legal and consent-only domains will need to be whitelisted, which is what CoinHive is trying to with authedmine.com
So people who don't run adblockers should just suck it up and get gut-punched because CoinHive doesn't want to lose money? CoinHive has the ability to just not pay out any versions of the software which aren't authmine. Again, what a bad look to partner with such a crap team of people. There are surely other providers of the exact same service.