safe_value only appears to be available for certain content types. It is not available for integers or real numbers. While I realize that an unsafe integer or real value cannot be input, there is the risk of coding [value] for such a field, that the field could be deleted and replaced by a text field.
The code would then become out-of-date because to be safe one would have to go back and change all references to [value] to read [safe-value].
It would be better if [safe-value] were always available to avoid this risk.