Background
I'm not sure if this is a bit of a self-explanatory question to many people, but I just can't figure this out. Tons of blogs made for writers, magazines, and other forms of media state that a debut author should not try submitting a manuscript of more than 100,000 words (or about 110,000 for fantasy). I don't think I've never seen anyone deny this.
Question
So,
Why do publishers not want to publish lengthy work from debut authors?
Personally, I think the story I'm writing would work best as a long, single book, about 150,000 words in total. I feel like if I were to start a second book in the series, I'd have too little to fill it with. My work would also work better if it were self-contained in a single book.
Would I be able to get away with what I just described, as a debut author who has never been published?
Thanks.