[rules-users] wrapping drools api?

Hello, some people write about wrapping the Drools API with an own access API for integration in the application. Sorry for the perhaps stupid question, but what is the reason for this? Does this only make sense if I'm thinking about changing the rule engine one day? If I'm not intending to change the rule engine from Drools to another, so isn't it the same if the developpers has to use the native Drools API or an self-written access API? Regards Tom