To be honest I'm not quite so sure either, but for some it just doesn't match the values the company wants to put out.
Most of big hosting company will not accept this kind of website due to prohibited by law in states. If you really want to host that website then "offshore" hosting is a must.
All sorts of reasons.. - Moral reasons - Potential legal issues in their country regarding the type of site - Potentual legal issues regarding specific content - age of models, types of acts shown etc. - Security reasons - more likely to be target of hacking attempts - Security reasons - if morals of site owner is dubious, do they really want them "let loose" on their network? - Safety reasons - porn and the potential links to organized crime - Excessive Traffic - even "unlimited" hosts have an limit. All hosts play "law of averages". Porn sites skew these massively. - Support time - large traffic sites cause more work in all parts of the operation such as networks, security, firewalls that the hoster is not necessarily paying for - Policy of the data-center being used forbids it - Policy of their network provider forbids it
I think a combination of what was said above is the best description of why some do not. Primarily traffic issues tend to trump even the most staunch of moral issues one might have.
The host in my signature does indeed allow for porn sites. As long as you comply with 2257 documentation requirements and ANY DMCA notices should you ever receive one, adhere to this and you'll be just fine. Good luck!
As with all things, since there are some that ban it completely, I'm sure there are some that specialize in pornographic web hosting. I would check into those
Pornography is prohibited by law in many countries. Most of big web hosting company are located in united states and have obey by state law.