They have oppressed women throughout the history.
They consider women inferior.
They limited their opportunities, they didn't allow them to be educated for a long time.
They don't respect women as much as they respect men. They don't take a woman seriously.
They harass women, catchall women and rape women.
They have curse words which often insult women. Ever heard of fatherf**ker?
Many times, people including women are referred to as 'he' and 'men'.
They allowed female foeticide, and girls moving to the in law's home after marriage.
In entertainment and media, fictional male characters are portrayed well and better than female characters.
Also, women have to take men's last name after the marriage and the middle name tends to be the father's or the husband's.
Plus, men hate it when a woman is better at something than them.