Partly it's due to the fact that the phonetic alphabet is a NATO standard, not just a US standard. So, you have people for whom English is not their first language, and so the words had to be easily pronounceable for everyone. That's why Able Baker Charlie Dog Easy (the old US standard) got changed to Alpha Bravo Charlie Delta Echo. That's also why we pronounce the phonetic "p" as pa-PA (emphasis on the 2nd syllable) instead of "PA-pa" (emphasis on the 1st syllable).
The other problem is that not every letter has the same sound in each language. F'rinstance, in your example of using "ceiling" for C, in some languages, the letter "C" doesn't exist - they use S or K. So, using "Ceiling," pronounced "Seeling" would be confusing for them.
Ah! Thanks!