Good question. That's what most Calvinists do. But, most churches aren't true Calvinists.
Most Calvinists will tell you they preach about Hell and Salvation (the Gospel) because the bible tells them to, then let the cookies crumble.
This is also what I have observed. In fact, one of the local Presbyterian churches has the word, "Evangelical" on their sign. [LWT scratches his head.]
Anyway, earlier on this thread or another one, cattails mentions the violence of John Calvin. Wasn't he merely imitating his Heavenly father? Nothing that John Calvin did even comes close to the violence that God himself will inflict upon billions of men, women and children.