Religions splinter. Protestants vs Catholics, Sunnis vs Shiites, Mormon This vs Mormon That. Even Buddhists aren't immune, nor are they above violence when Sect A meets Sect B. In essence, what splintering means is "we have a different opinion, and we (or you, or both) may be wrong". In practice, it means "we're right, you're wrong, and we're going to kill you". Come on, isn't that a little embarrassing?
We all want answers. Who are we? Why are we on this creek, and where's our paddle? The problem is, your Way is not my Way. Religions try to pretend that one size fits all. This harms us. And when one religion becomes two the harm is compounded exponentially. People may wonder "which is True?", but that's an invalid question. The proper question to ask is: "what makes these people so sure they have Truth?"
Maybe there was a Gautama. Maybe he was even as wise and enlightened as they say. And maybe we can even learn some lessons from his life and apply them to ours, just like maybe we can learn from the teachings of the possibly-mythical Jesus: "Be Excellent To Each Other" (oops, no, that was Bill and Ted). Come to think of it, we can--and should--learn from everyone! Well, maybe not Mohammed or Joseph Smith: neither is mythical, but both were scumbags.
Maybe there was a Gautama. If so, he's beyond our knowing or comprehension. If we try to find out about him or his life or his teachings, we'll quickly find conflicting opinions. Different sects. Different answers, all spouted off with blind certainty and therefore valueless.
What we need to learn is not what this guru's opinion is or that one's: that's just cult of personality. We need to find out how to learn for ourselves. Science helps with much of that, and I won't go into the pathos of religions who dismiss Science. But Science can't (yet) answer: How should I live my life? For that, we can have no certain or definitive or easy answers. Heck, we may not even find an answer... but we need to have our Way, and that must be our own.