Spelling Debate
There are two main ways of spelling the tea: maccha and matcha. The debate focuses on the transliteration of the ideographs making up maccha/matcha, which are matsu 抹 (ground) and cha 茶 (tea). When written together, they are spliced with a slight pause, called a "sokuon" in Japanese.
The debate is relevant because there is confusion as whether or not they are the same thing, or which is correct.
Maccha
Proponents of this spelling argue that "matcha" is an obsolete rendition of the Japanese, based on an older version of Hepburn romanisation. They also argue that most Japanese native speakers will write “maccha” if asked to write the word romanised. It is also the spelling noted in the Bibliography of Japanese Language, used by most University professors. In summary, they feel the word belongs to Japanese people, and should follow Japanese popular usage and governmental policy.
In the interest of having uniform spelling rules for romanised Japanese, the government has officially adopted the traditional Kunrei-shiki system with popularly used Hepburn spelling as acceptable Version 2 spellings. Japanese romanises the sokuon with a doubling of the constantan. Therefore leaf would be written happa, made would be tsukutta, and map would be mappu. However, Hepburn used to romanise the double c as a tc, thus the matcha spelling. Because few Japanese are aware of this rule, and few Professors teach it, this aspect of Hepburn was not included in the new system. The Cultural Affairs Agency can be reached at +81-3-5253-4111 to confirm this.
Proponents of maccha argue that the matcha spelling is a mistaken transliteration of Japanese made only to benefit English speakers. Although other Japanese words such as sake are often mispronounced as rhyming with kay, as opposed to the correct key, the spelling is not altered to make the word anglosized.
Matcha
Proponents of this spelling argue that it is popularly used in Japan and North America. This can be ascertained by the vast amount of search results on most internet search engines. It is also easier for English speakers to pronounce the word with its guttural stop, when the t is introduced. It finds historical backing in the Hepburn system, long used when teaching Japanese to JSL learners.
They argue that maccha is not widely used in Japan, and that government does not back the maccha spelling.
Neutral
Those neutral in this debate argue that the alphabet is not historically used by the Japanese, and therefore any transliteration that has even mediocre popular usage, should be considered correct, alongside more popular spellings. They argue that nobody truly owns the spelling of Japanese.