Are you suggesting that Islam is largely true with only the need of "reform", or that a reformation intrinsically undermines any organized religion, none of which is any truer than another?
I am not an expert on comparative religions. I will share my feelings, which are not those of an "expert."
I am making an observation that there seem to be Muslims that I have known and that have seemed to exist in different parts of the world that have at times lived in harmony with their non-muslim neighbors. If the beliefs of those Muslims can become the dominate beliefs of that religion, that that I what I would hope in a "reformation."
As to "...any organized religion, none of which is any truer than another..." I would have to say that to a certain extent I do believe that. If someone is a Mormon and lives a good life I would hope that they are not condemned to eternal damnation. If someone is a Catholic and lives honorably I would hope for their salvation. Likewise if some one is Bahia, I have no problem with their practicing their religion. If a Buddhist, such as the Dalia Lama, lives a thoughtful and respectful life, I do not see his having a lesser life than my own. I see them each in their own way as doing God's work.
I am no more saying that Islam is "largely true" than I would debate whether the Greek Orthodox religion is more true than the Catholic religion. I will also not debate whether the Mormon religion or Christian Scientist "religions" are "largely true." I will leave those debates for others.
While I am not saying that the Muslim religion is "largely true," I will say that Islamic Fundamentalism seems to me to be "largely wrong." To the extent that people of the Muslim religion can respect their neighbors who may be of different beliefs, then I can accept that religion as having some societal value.
From what I know, I would say that the Saudi money behind the Wahhabi Muslim fundamentalists, is a big part of the current world terrorism problem. I feel that all civilized people should unit against such hateful and intolerant preaching. If the Muslim people of the world can "reform" their religion to allow tolerance for others, then there is no need to wipe the Muslim religion off the face of the earth.
I have a personal friend who is a Suffi. At his wedding, party I had the opportunity to speak to many of his other friends and listen to their prayer. I feel comfortable that I and others could live in harmony with him and his friends. There are many other Muslims I would not feel that way about.