Feminism is the belief that women should have rights that are equal to or greater than the rights than men have.
It is not about equality between the genders as such. It is the belief that women should be involved in a continuing battle for better circumstances than they currently have. The focus tends to be on areas where women are perceived to be at a disadvantage, however their is no requirement (in their own mind) for a feminist to also seek to help areas where men are perceived to be at a disadvantage.
Unfortunately this drive for something better for women, rather than for equality, is what turns so many women and most men away from feminism. Most people would accept that the sexes should be treated equally, but this is not what feminism is really about.
It may help to compare it to a Trade Union. The TU is there to represent their members and to get them a better deal. This is a continuing drive for better pay, better conditions for their members. If the management cede to their demands, the union goes away and thinks about what else it could lobby for. The union isn't considering the effect on the employer, or even non-union workers in the same industry, except in relation to the drive for "more" for their members only.
Feminism of course has many advocates who will argue, sometimes convincingly, that women have been disadvantaged for so long that it is only right that their only target is improved rights for women, not equality. This turns many people away though. Rationally, why should the current generation of men be punished for the actions of their grandfathers and great-grandfathers (and great-great-grandfathers, and so on)?
The feminist ideology is rightly perceived as inflexible. Whether this inflexibility is justified is a matter for debate, but there is no compromise on the key principle: better rights for women, which are equal or superior to those enjoyed by men.