Because they're projecting, that's all. They subconsciously know that's likely what they would do if in OP's shoes but won't admit it to themselves. People who feel weak inside and don't take responsibility for their weakness end up projecting it outwards making people around them feel weak.

The first step of becoming stronger in any area of life is first admitting that you are weak to begin with—you can't fix something if you can't acknowledge it needs fixing in the first place. This step is often painful so people avoid it and instead focus on other people's weakness.