I grew up in a church that was very serious about "serious" preaching- Primitive Baptist, very focused on Calvinist doctrine and what could be considered scriptural literalism. It was definitely not "baby food"... but they still could not answer some questions clearly, and that is because it is an invention of man rooted in a prescientific understanding of the world. I would argue that church are losing members not because it is being watered down, but because it is losing relevance.