Yeah, I'm not actually sure what OP meant, now. If your kid's in Sunday school, aren't you going to be spending time in the service, anyway? I guess if you just dropped them and ran, it'd be hard for them to say no.

Maybe you could get away with that when they're really little. Once they're school aged, leaving them unsupervised would be better than in the hands of whatever bunch of church ladies, and the Catholic church has a whole other layer of reputation.

From their perspective, we're the ones trying to hide our children from ideas that are correct and vital, so they can justify it to themselves. Trying to defend the standard, evangelical version of hell is harder, which is why it's good to bring up.