Catholics go to Mass because they want to worship God together, and are mindful of Jesus’ promise “where two or more are gathered in my name, there am I among them”, or that Catholics believe Jesus is present in the Eucharist. Such explanations will probably be lost on someone who has no sense of what Mass is about or what it means to Catholics; or perhaps doesn’t even believe that there is a God and that death is not, in fact, the end of our conscious existence.
However, Jacob may be interested in sport, so I could try and offer an analogy: Why don’t people wake up and stop supporting the primitive tribalism inherent in following a football team; the abuse from coaches and fans when ‘encouraging’ the players; the money and greed that is the basis of it all in fees, merchandise, and so on — especially when everyone knows the hooliganism and violence inherent in such activity. And despite Bill Shankley’s famous saying that “football is more serious than life and death”, Catholics regard what happens after death as more serious!
Jacob Goode might reasonably respond that this description of football is a gross and unfair caricature, and that’s not what football is all about. And so it is with the Church and Mass.