They filled a nieche when paypal refused to take money for gambling. It is legal in UK, skrill is based in Ireland. As a wallet provider they do offer the service of exchanging money into crypto and having it on the wallet. At least in some countries. For regular use they try to compete with paypal by essentially providing the same service.
Imposing arbitrary morals onto payments is not what a payment provider should do. If it is ok for credit card companies, it should be ok for a service based on credit cards.