It's not a consequence of that, what you're describing is a consequence of poor justification algorithms + no manual justification. For books, generally want block justified text without rivers, that's why you need a good tweakable algorithm, which is what GP is complaining about. Lack of that makes it problematic for use in professional publishing work

Even with very good justification tools (InDesign's being the obvious example, as it's a direct competitor) a professional end result still requires a lot of manual work -- adjusting tracking and kerning, actually editing the text. But without that solid basis it's entirely slow manual work.