The greatness of of word Tamil and its contraversial writingTamil is a language which has got less alphabets than its other Dravidian sister languages like Malayalam, Kannada, Telugu and the Aryan language Hindi. English has got less alphabets than Tamil and has only one "L". Whereas Tamil has three types of "L" (eg L LL Zh) .The Malayalam alphabet also has the same "L" like Tamil. Kannada alphabets has only two L and LL. Hindi alphabets has only one "L". Therefore writing Tamil as Tamizh will be understood and pronounced correctly only by the Tamil and Malayalam speaking people. We cannot expect a Englishman or a North Indian to understand this complicated special word ZH.
To conclude: When a Tamilian communicates with other Tamilian he may write it as "TAMIZH". But when a Non tamilian communicates it will be certainly written as "TAMIL" and we cannot claim that he is wrong in his writing .
TAMIZH is for the Originals - TAMIL is for the foreigners