Do you think Japanese people actually read and write in kunrei-shiki? No, they write using their own letters.
Romanization is an approximation that exists primarily for two purposes: 1. to express Japanese terms in other languages and 2. to enable typing Japanese on a computer. It’s silly to enforce kunrei-shiki, a system rarely used in practice, in the name of "accuracy" based on arbitrary criteria. Romanized spellings will never be accurate for obvious reasons.
Given the purpose of romanization, it’s more practical to choose a system that allows non-Japanese speakers to pronounce words more closely aligned with the correct pronunciation.
What I’m complaining about is that the romanization is based specifically on English, arbitrarily chosen from all languages that natively use the Latin alphabet. For example, what’s transcribed as “shi” is only “aligned with the correct pronunciation” for English speakers. In other languages it would be more accurately transcribed as “ši”, “szi“, “chi”, “schi” or even “si”.