This depends on the attitude and behavior of the individuals using the website. Some muslim websites require disclosures regarding the strictness of adherence to religious practices. This could be helpful to those wishing to find a likeminded partner who shares the same level of religious fervor. For those not wishing to date outside of their culture and religion, a muslim website may seem to be the obvious choice. However, as with any dating website, extreme caution is advised as there are risks and dangers involved when you disclose information about yourself to a complete stranger.
Religious values are not the same everywhere the religion is practiced. Some versions of Christianity, for instance, are more strict than others. The same is true with Islam. In some parts of the world and some parts of the country, rules about dating in Islam are more stringent, and in others they are more relaxed. It wouldn’t be fair to say that the websites setup for Muslim singles who want to meet other unmarried people who share their faith are doing so in a way that necessarily pollutes the religion. If anything, Muslim singles websites would reinforce the value of marrying within Islam.