When you get right down to it, North Americans are the ones with the odd pronunciation of the letter Z:
Letter | German | Dutch | French | UK English | US English |
B | /beː/ | /be/ | /be/ | /biː/ | /biː/ |
D | /deː/ | /de/ | /de/ | /diː/ | /diː/ |
Z | /t͡sɛt/ | /zɛt/ | /zɛd/ | /zɛd/ | /ziː/ |
The etymology of the non-US pronunciation is that the letter z goes back to ζ, the Greek letter zeta. However, in the USA the pronunciation is based on dialectic English pronunciation from the 17th century, where it got put into the same "category" as B, D, P, T, etc. (The change in pronunciation from /e/ to /iː/ is because of the Great English Vowel Shift, BTW: until about that same 17th century, the letters' names would have been /be/, /pe/ etc. in English too.)