This bug may be related. https://developer.blender.org/T52780
Manjaro KDE Linux 10.10.18
Blender 2.8 10.10.18 and 2.79b
Nvidia GTX 580
The sculpt simplify brush has no entry in the main brush picture menu. This causes odd menu behavior like changing the icons to other icons when you select it through the text menu system. May have also crashed blender but this might also have been and undo fail, could not reproduce that problem.
Was stated in the other bug report that the use case was unknown. I find it useful when I have dynamic set to a small number like 2 and then have to many verts thus a slow down. You can change it to 8 and go over your work to change the mesh density back up to something workable.