User blog comment:Rappy 4187/Technical Update: September 23, 2015/@comment-24473195-20150923203110/@comment-24473195-20150924200542

A public bug tracker is a double-edged sword. While it may create a common point of reference to see bugs, it may also expose unnecessary technical details to non-techies. The vast majority of wikians probably couldn't care less if a bug is tracked or not, as long as it is eventually solved. It may also sometimes create the expectation that some rare bugs may eventually be solved.

When one uses C they automatically pick up the browser, the OS, and possibly even the wikia in question, which greatly reduces the questions they need to ask, and make it easier to triage the bug.

Using Wikimedia as an example, some users report their problems in a central wiki, others report them locally in talk pages, some both,  others submit emails, others simply complain in talk pages, and most  probably don't provide enough information. So, I'd prefer spamming a C link anyday over recreating that complicated issue.

That being said, a public tracker is generally a better solution if it is implemented properly.