Anything that gets learned incorrectly as "a beginner" needs to be unlearned later which is a waste of time and effort and likely has caused many students of the language to give up. I do wonder if some of Cantonese's reputation for being notoriously difficult for Westerners to learn is a function of the quality of learning materials used.Quote
MatFayLong
However the book doesn't use any numerical tone system, only accents on different parts of each word. If someone is brand new to Cantonese then Yale or Jyutping systems won't be mentioned at all. I know, for me, when I started with the tones they were too difficult but I can see how an intermediate learner would find them necessary.
Yale, Jyutping, or even IPA take some learning, but do pay off. Imprecise (and/or inconsistent) transliteration schemes might seem helpful at first, but are more of a hindrance than a help. On the flip side, there are some transliteration schemes such as [en.wikipedia.org] that are too complicated for their own good (in this case with respect to how tones are represented).
One who buys language books from the Mainland will encounter [en.wikipedia.org] as well. It's not as bad as it first appears.
-Tony