[hunter2_]

As an English speaker who has traveled to Japan without learning much of the Japanese language, I agree generally but I also noticed that there are some cases where a vowel is written but not pronounced. For example, "gosaimasu" is mostly pronounced without the "u" (creating a counterpoint against final consonant other than "n" being forbidden) and "gozaimashita" is mostly pronounced without the second "i" (creating a counterpoint against consonant clusters such as "sht" being forbidden). It gives me the impression that these rules exist more in written Japanese than spoken Japanese, at which point it becomes less clear why adding a vowel to the end of foreign/imported words is so common. Maybe it's just my English perception that the sounds /s/ and /sh/ consist of pronouncing only a consonant, when in reality the fact that those sounds have duration (not just a moment) actually means it's more of a vowel even when totally unvoiced!

[hunter2_]

As I think on this further, even these voiceless /s/ and /sh/ sounds involve putting the lips into either an /u/ or an /i/ shape based on the following vowel even if that is also voiceless, creating that which is not a syllable in English, but perhaps is for this purpose in Japanese. The C-V cadence and final vowel (given lack of final -n) rules are satisfied...