I've got no problem with their operation, but YOU are going down a VERY dangerous and slippery slope by saying I can't block domains that clearly host trash because they might host something else.
On my network I can block child porn, malware sites, scam sites and even entertainment sites like youtube. If you are running a service that mixes the content together, then you may be blocked by folks (like me) who don't have time to chase down every (free) subdomain you allow scammers to create.
That is my right. Period. Full stop. That is not censorship.
Folks here get censorship confused. The govt does virtually nothing to stop these scam sites - so they are certainly not being censored. I'm fine if govt does nothing, as long as communities of people can block these places.
And yes, if you run a site on the internet and don't make it slightly difficult for scammers to use your site to host crap, then other folks in the neighborhood will move the heck away from you.