Mostly because people who don't want to change because they have a vested interest in maintaining their current opinion. The reasons are sometimes political, religious, financial, etc. But mostly, it's ego.
Changing their views means they might appear weak, indecisive, wishy-washy, or just plain different from their peer group. They run the risk of being ostracized from the group. And being ostracized is worse than standing up for their beliefs, for what's right, especially for women. There's comfort of being in a group.
Then you get to the politicians. The alleged decision makers. Any politician knows, either from experience or wisdom passed on by mentors/advisors, that stating an raw, unsanitized opinion is political suicide. Politicians are in it for their egos. They have no overriding need/desire/motivation to do the right thing. They're seduced by the power, the prestige, the money. Their sole interest is getting elected, and staying elected.
In the hands of a skilled interrogator, a politician's position on any major issue, be it immigration, labor, health care, abortion, etc., can be skillfully led down a path where, by choosing simple A or B answers, they eventually will reach a point where their position is flipped 180 degrees, in direct violation of their beliefs, values, and political platform.
Staying elected means being non-committal and not saying the wrong thing to any one at any time. Especially reporters...
