The main thesis here is good, but that’s a mischaracterization of what people consider “failed” writers.

Someone who wrote one novel and had it published is not considered a failed writer, no matter if they then stop writing immediately. “Failed writer” is pretty much reserved for people who tried writing and couldn’t get anyone interested enough in it to publish it.

I’m not sure what labels would be applied to someone who exclusively pursued self-publishing, but that’s not really the common way.