I've found not only that our beliefs have absolutely no effect on facts, but also that the inverse should be true. On this forum it has been accepted that "Calvinism" refers not to the Presbyterian denomination but to the so called "five-points" from the Canons of Dort. From Article 15 of the first Main Point of Doctrine: “And this is the decree of reprobation, which does not at all make God the author of sin (a blasphemous thought!) but rather its fearful, irreproachable, just judge and avenger.”
While there certainly may be Calvinists who believe God authors sin, such belief is contrary to the doctrines of Calvinism itself. This fact (as stated in the Canons of Dort, which attributes the idea that God authors sin as a blasphemous thought) is not something that can be honestly debated. That said, we have had what I have referred to as neo-Calvinists here (I don't know why as they have their own forum, i.e., the dog house) that hold "hyper" views (views taken from Calvinism but to unwarranted conclusions). But the idea God authors sin is a departure from actual Calvinistic doctrine.
Free-will advocates have the same issue. There are people who share a common view in terms of the mode of divine knowledge, but take it to the unwarranted conclusion of Open Theism. In terms of the atonement, I believe the most dominant view in Scripture is the Christus Victor motif. But some, like Denny Weaver, take this to the extreme of denying penal substitution to create a non-violent atonement.
But, the bottom line is Calvinistic doctrine proves you are mistaking here (regardless of what some Calvinists may believe or teach). Likewise, Arminian doctrine proves others who would demonize the view wrong for the same reasons - Arminian doctrine clearly states that God, not man, is the author of salvation.