I sincerely am not sectarian that I know of. I really appreciate, for example, HHDL's contributions to the Rime movement in Tibetan Buddhism.
That said, am I the only one who feels like, "If it's not broken, don't fix it?" I feel uncomfortable with the idea of too much change to accommodate any different region, culture, person, etc. where Buddhism takes root.
Please tell me if this sounds restrictive, rigid, or sectarian. But I honestly wouldn't want a Theravadan to change his/her thing to accommodate me, nor would I want to change my own religion to melt and blend with others. Different is fine, and it's interesting!
Conquer the angry man by love. Conquer the ill-natured man by goodness. Conquer the miser with generosity. Conquer the liar with truth. -The Dhammapada