"Kunrei-shiki romanisation for つなみ is 'tunami' "

I selected tsunami because of its very common usage and rapid rise in English (I'm old enough to watch it happen), and that most English speakers pronounce it differently to its accepted English spelling.

I've actually discussed the pronunciation with native Japanese speakers and several have told me that the correct pronunciation is somewhere between tsu and tu, the tsu is too hard and the tu too soft. That's another debate for linguists and language experts which I am not.

My post and follow-up reply are principally aimed at English and English speakers and language training in anglophone countries. As I mentioned, pronunciation matters because for many people upon hearing a word mispronounced it takes additional time to mentally process it which distracts from what is being said.

The real issue here is not whether that some linguist translated the word with tsu or tu but rather that once the romanisation was agreed upon then there ought to be an agreed pronunciation based on that spelling. That's principally my point.

No doubt tsu is uncommon in other English spellings but the usage of the word tsunami is very common so it ought to be incumbent on public speakers to pronounce it correctly. I believe this comes down to poor language training. Why training matters can be inferred from my other imported word zeitgeist, pronouncing it is never a problem because English is a Germanic language, thus it has common roots with German. Again I'd stress I'm not a linguist and my objection is purely practical, I find bad pronouncation very distracting.

I think your use of (ph)thalic acid, (p)terodactyl, etc. is stretching it a bit. These scientific and technical words are not as in as common useage (on the say the daily news) as tsunami is but I concede their usage is growing. It's unfair to criticize people who cannot pronounce strange and or uncommon words at least without some practice. I spent years studying organic chemistry and I still have difficulty in pronouncing some of the rarer functional groups. Take a look at the official IUPAC list of chemical names, I defy most experienced chemists to pronounce many of those names upon first sight.

Re your point about the strangeness of English spelling and pronunciation, (k)nife, (g)nome, etc., that's a whole new subject which I've not time to discuss here execpt to say if you don't already watch the YouTube channels Robwords and Words Unravelled then you ought to do so. Anyone interested in words and language would find them most interesting.

Edit: I forgot to mention the meaning of the expression 'tital wave' was taught to us at a very eary age and it had the same meaning and connotation as tsunami. We learned about tidal waves in social studies in primary school. I'm surprised this was even raised as knowledge about the term across the population was so well known that querying it would have been considered strange. It seems tsunami has done more damage to our language that I'd have thought.