I took the time to enjoy this thread and it's myriad views. Great sport and entertainment, a genuine thank you to one and all.

My personal slant is that 'foreign' words should be correctly singulariSed or pluraliSed (guess which side of the pond I'm from?) regardless of the era of origin, as with graffitti and scampi which have more recently entered common English usage.

My personal bug-bears are the musical terms sonata, solo and concerto, often mis-pluralised with the additon of an 's'.

P.S. I agree it should be maths as in the UK, it being a contraction of mathematics.

P.P.S. Don't get me started on stressed syllables in pronunciation. I can never understand in the US why the herb is pronounced oREGano but the state is OregON. Why not oregAno or oREGon? Then why not aVOCado, TOMato and POTato? Any road up, if it wasn't for a quirk of fate this whole thread would be in Spanish!