If you're used to the GitHub pull request style, you'd be more likely to make a small commit and add it to the request. In gerrit that approach results in a separate patch for review, which isn't what such a person would want.
(Personally, I've come to appreciate gerrit's model for strongly encouraging building patches that are encapsulated single-reviewable-changes, in a way that lends itself to never having a commit that'd break the build if you landed on it e.g. during a git bisect.... But it's also something that surprises people who've not used gerrit before, in my experience.)
It's a power user tool that has a slight learning curve.
GitHub and others are frequently code browsing tools first, with code review coming second. "Code hosting has look like GitHub" is unfortunately a common myopia.
Phabricator (from the little I used it) seems closer to Gerrit than other code hosting.