I believe the virgins in question are perpetual virgins, i.e. their virginity grows back. Personally I think I'd find it quite tedious to have to perpetually deflower 70 women, but to each his own.
At least the Muslim paradise, unlike the JW version, gives them something to really look forward to. They're denied sex on earth; they get an abundance of it in heaven; on earth, they avoid alcohol, in heaven wine flows freely; on earth, they spend most of their time praying and purifying themselves, in heaven they are perpetually pure; on earth, the pig is a disgusting unclean animal, in heaven, it's everlasting pork chops all round!
JWs however probably lose the few pleasures they have in life. Now they've got television and fried food; in the paradise they'll have placid wild animals to stroke and fresh fruit and vegetables to eat. Sex, if it features at all, will be with the same person for all eternity. The most they have to look forward to is meeting their favourite bible character.
Still, it probably beats the Christian heaven where the dream is to sit on a cloud praising God for eternity.
The atheist future of eternal nothingness strikes me as far more appealing than any of those options.