I dont wana go OT but why is he THE Rebbe?
because by other chasidic courts the grand rabbi is referred to as the rebbuh, only by chabad do they refer to him as the rebbe, emphasis on the e (either pronounced as a hard e or as in eh)
looks like your not familiar with many chasidim because most of them refer to their rebbe with 'e' as in 'eh' not Rebbuh.
im familiar with many, but not all. do tell which other chassidim refer to their leader as rebbeh
Any Galizianer, Polisher, Hungirian etc. Chasidus. which don't?
ive spoken to many a chassid, and outside of chabad ive only heard rebbih or rebbuh. only in chabad ive heard rebbeh and rebbee