Christianity isn't alone in vilifying suicide. Click the link. Even non-Abrahamic religions condemn it. Whether you believe in a particular faith or not, whether you believe in religion as divinely inspired or constructed by man, either way for the most part suicide is something that is recognized as harmful to individuals and/or society and needs to be addressed and discouraged.
I know you don't believe me, but I understand what you're saying and the perspective you're coming from. I'm not dismissing it, I'm not downplaying it, and I'm not saying you're wrong. What I am saying is that religious institutions are flawed because we're flawed, that their short comings are a result because of the limitations of our humanity, and that as we as societies and individuals change and develop, we can see reflections in the changes of our values in religious institutions.