Here's why:

* Nucleoli are not essential for all cells: While nucleoli are crucial for ribosome biogenesis, some cells have specialized functions that don't require active protein synthesis. These cells may have reduced or absent nucleoli.

* Nucleoli can be transient: In some cell types, nucleoli might appear and disappear depending on the cell's activity and stage of development.

Instead of a specific name for cells without nucleoli, it's more accurate to describe them based on their characteristics or function:

* Cells with low protein synthesis: These cells might have reduced or absent nucleoli.

* Specialized cells: Some cells have unique functions that may not require active ribosome production, leading to reduced or absent nucleoli.

In summary: Rather than a distinct category, the absence of nucleoli is usually linked to specific cell types or states where active ribosome production is not necessary.