Originally Posted by Nell2ThaIzzay
It was personal hatred for what his son did, alongside a genuine hatred for mutants and wanting to completely eradicate them into extinction.
The movie establishes that Stryker wanted his son cured before Jason ever did what he did to Stryker's wife.
Yes, it was a personal thing. It wasn't the whole society divided around mutants, as in X1 or X3.