Definitely not the only one. The language is poor. "Heading Labels" or "Option Heading Labels" would be a much clearer way to describe this option than "Left Column Labels."
Why?
(1) "Left Column Labels" implies there are "Right Column Labels" and maybe "Center Column Labels." One of multiple kinds of labels, in any case, for sure. Which in fact there are not. There is one kind of label, which happens to be typeset flush left. All the qualification "Left Column" does is mislead, creating the false idea of other kinds of labels from which these are distinguished. The reader wondering what labels are referred to will be looking for an object having a "left column" instance as well as other instances.
(2) Four options up on the "General Setup" screen is the option "Dashboard Columns" to select the number of visual layout columns for the dashboard web page. "Column" here is the commonly-known typesetting and visual layout term, used for both print and visual layout on web pages, in advertising, and so on. A two-column design, a one-column ad, columns gutters margins, etc. A reader who is carefully looking down the setup page will have this idea of what a column is when they get to "Left Column Labels" below. This time, however, "column" is a technical term referring to an HTML implementation of a visual Label or Heading. It's not a visual column, it's a programming strategy to implement a visual flush-left heading label (flush-left within a single layout "column"). Even readers very familiar with columns as a low-level typesetting implementation (e.g., HTML, LaTeX) can miss the fact that the meaning of "column" has changed.