Hi,
Macros in 'rulerformat' reflect number of entries in the current list, hence .. (not sure why it's . on the screenshot) is counted when present.
You can hide .. by changing 'dotdirs' which will affect number of entries.
Affecting the count while keeping the entry will take adding new macros (although not really sure what to do about tree-views with multiple .. entries) or allowing formatting 'rulerformat' in Lua.