I have a feeling that there's maybe more motive for WWE's decision. This one incident may just have been the final nail in the coffin.
While Nick the son was in prison for the car crash that left his buddy a vegetable, an audio tape of Hulk talking with Nick on the jail's phone was leaked. In it, Hogan not only showed no concern or remorse for the victim, but can even be heard telling Nick, "Maybe we can get a TV deal out of this!"
A few years after that was a messy divorce in which many harsh allegations against Hulk were made public. Regardless if true or not, they did not boost his image.
Shortly after the divorce came the sex tape - nothing positive about that.
Or, maybe Hogan's choice of vocabulary was the sole catalyst for his release. Racism is an issue that is publicly hotter than ever in light of recent events such as those in Baltimore and South Carolina.
Either way, being a publicly traded company with shareholders already distressed over plummeting stock values, WWE's recent decision only seems logical.