The phrase/question "Who am I to---" is usually followed by words like "judge" or "criticize", and depending on the circumstances, are probably appropriate, but this isn't one of those times. At least, not where I'm concerned.
I have a co-worker that is also a writer, he's been working on his book for about a decade, piece meal as inspiration strikes, stuck on grammar and syntax. He's reworking sentences and paragraphs until he thinks they're perfect, neglecting the flow that wants to happen naturally. So, I've offered him a challenge, one that's meant to help me as well. Write so many words a week/day. The idea is for him to turn off his internal editor and me to get my butt in gear. He mentioned asking me to read a few pages of what he's worked on. I'm looking forward to. But it's been a month and a half. So, I brought in pages of my work in progress to share with him and to get his feedback.
He said "who am I to critique this? You're doing it and I'm not."
Um, I don't know. A reader. A writer. Another pair of eyes. He could have been the leader of a special forces team involved with highly covert operations before joining the current manual labor staff. I don't know. I do know that I know my story inside out and that I will automatically add whatever information I need to make the story make sense. Someone who doesn't have complete access to the story and world before reading, won't add that information. Therefore, logic dictates that if all of the information isn't present it won't make any sense. Words and grammar may not make any sense either because, not only does the writer make mistakes, computers can't catch everything. They aren't programmed to do that.
I'm not sure who said it, or even it can be attributed to one person, but every author, regardless of their success can benefit from an editor and a beta reader. Because, seriously, there are no minor details in books.
And as for the rest of his comment, publication is completely and utterly out of the realm of possibility if the book isn't finished. Once you reach the end of the book, even if it's a world epic spanning 10 novels, reaching 'the end' of the story you need to tell in that first book and each subsequent book puts publication firmly with in the realm of possibility.