I found the Richard III Society website to be very helpful in my research on him, as it presents one point of view. The society was set up in 1924, to defend the way the late king has been vilified by historians, mainly of the Tudor period, which culminated in the way he has been portrayed by Shakespeare in his play Richard III.
IMO, Richard was not nearly as evil as he was portrayed by Tudor historians such as Polydore Vergil, Edward Hall and St Thomas More. It may have been worth their heads to suggest anything different, in those times.
You may say they are a special interest group, you may say that it is propaganda, but so are the opinions of these Tudor historians. The views of the Richard III Society were first aired by Horace Walpole in 1768, nearly 250 years ago, so they are nothing new. Since then, many reputable historians have looked at the evidence and questioned whether Richard was indeed hunchbacked or evil (the two were often linked in mediaeval times).
So things may not be as cut and dried as you may think, because history is usually written by the victors.