But some Baha'is have said that all of the other religions have added in "traditions" of man and/ or have misinterpreted their own Scriptures. Those Baha'is are not accepting the other religions as is. To be complete, it sounds more like those Baha'is expect people in the other religions to recognize that the Baha'i Faith is the fulfillment and continuation of their old religion. And that if they only take and look, they will see that as being true and become Baha'is and drop out of their old religion.
As for adding traditions onto the original teachings of any religion, this is true, independently of anything Bahá’ís say. It’s observable reality. The Christianity of today is not the same as the Christianity of Jesus’s Time, nor is the Buddhism of today the same as when Lord Buddha first appeared. Of course, though, this principle is true for practically everything in existence. It doesn’t stay the same as it was originally; it changes over time.
As for misinterpreting their own scriptures, again, I wouldn’t deny that in certain respects (again, independently of Bahá’í teachings), certain followers of various religions have distorted the teachings. Take Jews for example, some of whom had taken the Biblical idea of themselves as a chosen people way past the point of calling others to a life of holiness and purity of heart and turned it into a grossly inaccurate idea of non-Jews being inherently impure or inferior to them, which wasn’t the original purpose of that teaching.
As to this claim made that Bahá’ís don’t accept other religions as is, this is wrong. We do. With this said, however, just because someone accepts that a religion teaches what it does does not necessarily mean that they agree with every single thing that religion teaches. Take for example, the Biblical idea that Jesus Christ was bodily resurrected. It is true that the Bible plainly teaches the bodily resurrection, but it does not follow that because a person acknowledges the validity of the Bible as sacred and of the person of Christ Jesus as a Divine Teacher, the person has to accept that belief wholesale. Otherwise, he or she would be a Christian themselves. Have I spoken falsely thus far?
As for the fulfillment of prophetic expectations of various religions, I leave the deep diving into those more to Bahá’ís from those specific backgrounds. I’m going to speak as a person from a devout Christian upbringing. Admittedly, when I first encountered Bahá’u’lláh’s claim to be the Return of Christ, truthfully I was very skeptical, and not just skeptical, I had felt livid. How could this man from Persia be the Second Coming of my Jesus, right?? Without even giving Him a chance to really explain Himself, I became upset with Bahá’u’lláh. But then, something led me to explore what He was talking about. What did I discover? I discovered that He meant something different by the concept of ‘Return’ than I had initially thought. By the idea of ‘Return’, Bahá’u’lláh meant that the attributes and qualities of the Spirit of Christ would manifest in a new person, Himself. It was like a lightbulb went off in my head! (“Ohhhhh. That’s what He meant.”, I said.) Everything after that began to click for me.
Accepting Bahá’u’lláh’s claims is a matter of the person’s own heart and mind. You’re absolutely right on that, CG. Though, I will say that in terms of the completeness that people of diverse backgrounds feel, it comes more from Bahá’u’lláh’s conception of religion as one harmonious whole, glimpsed through different outward forms, from different teachers, than any particular fulfillment of prophecy.