Usually, commentaries are short articles that draw attention to or present criticism on a previously published article, book, or report, often using the findings as a call to action or to highlight a few points of wider relevance to the field. Commentaries do have credibility, however not as much as an original research paper. This is because commentaries do not include original data and are heavily dependent on the author’s perspective or anecdotal evidence from the author’s personal experience to support the argument.
The reason why the editor may have told you to publish your paper as a commentary may be because your paper does not include a significant amount of data. However, if your paper has a good amount of data and you strongly feel that it can be an original research article, then you could submit it to another journal and get their view first. If the second journal also says the same thing, you can be certain that your paper cannot be published as an original article. In that case, you can shorten it and resubmit to the first journal as a commentary.