The issue I have with it, is that people are going to have a certain image in their mind when someone says "rape" and I don't think digital penetration deserves to have that label applied to it.
They are both bad but, and excuse me for being graphic, the image of a man holding a woman down, forcing his penis inside her, then having sex until he climaxes, is not the same as a man inserting his finger into her.
The reason it seems misandrist to me is that it feels like some people specifically want that label/image to be attached to a man who has not actually done that thing.