I think DevArt is under pressure from the pay services like PayPal and the cards like Mastercard, Visa etc. and probably wants to attract more 'mainstream' advertising. ImageMaker has had similar problems with CruxDreams, but CF isn't a paysite and carries no adverts (well, only ones that no longer pay!), which is why we have the monthly appeals for funds.
As to what can be posted here 'unexpurgated', we're pretty broad-minded, but there are some things still freely available on DA that we wouldn't allow, especially on age grounds.