This is a follow-up to status-completed report Suppress “Stack Exchange” part of site names in the lists of sites.
The list of top users has recently developed the same problem: incessant repetition of "Stack Exchange", redundant on a page with "Stack Exchange" in large letters on top.
This wasn't the case last December, per Wayback Machine.
According to Adam Lear, this is a side effect of a data model change, i.e., a bug.
Same bug is present on the list of moderators.