Whatever you my think his intentions were, his actions set in motion fragmentation that inhibited the spread of Christianity and insured more of those born into Christian countries would be damned since there were thousands of "Christs" to pick from. Naturally, only the spirit could tell them whether theirs was the right one or not and the majority of those alternative "Christs" didn't dictate major behavioral changes since everything revolved around how the individual interpreted scriptures anyway.
Whether you think he was right or wrong theologically, it's a fact that he did the wrong thing by leaving rather than reforming.
Martin Luther was a man, a sinner. I do not hold him in awe, but I do believe God used him as a tool to bring his pure Word back into worship.
Martin Luther did not “stay and fight” because the RCC ex-communicated him from the church for not retracting his statements of the 95 Theses. M. Luther said he would fully retract if he were proven wrong in the Bible, the RCC refused debate. The Emperor Charles declared him an outlaw whom anyone could kill after 20 days.
He clearly had no chance to “stay and fight” The RCC and the German Govt. made sure of this.