We are not saying DNA is like a message. Rather, DNA is a message.
A key characteristic of life is active transport: control over what enters and exits the cell. Closer looks reveal exquisite “selectivity filters” with moving parts that make active transport work.
Genomics has come a long way since the central dogma and junk DNA. If you expect to find reasons for things, you often do find them.
The impressive complexities of proteins, nucleic acids, and other biological molecules are presently developed in nature only in living things.
Perhaps scientists fear that acceptance of this conclusion would open the door to the possibility (or the necessity) of a supernatural origin of life.