The first thing to note is that she's a lesbian who thinks that other women should also be lesbian. That makes sense if you really believe in FTP - feminist patriarchy theory.
According to this theory, men have arranged society so that they benefit from the oppression of women and men, as a class, enforce this privilege by acts of violence against women. If this were true, then it would make little sense for women to love men, as they would be loving those who violently oppress them.
And so Julie Bindel in one article urged bisexual women to stop sleeping with the enemy (i.e. men):
When I write about making a positive choice to be a lesbian, and that I believe there is no gay (or for that matter bisexual) "gene," I am accused of being an ideological robot and therefore not genuinely sexually attracted to women. That is nonsense.
...For bisexual women living under the tyranny of sexism, choosing to be lesbian is a liberatory act.
Those of us who grew up in a time and context where there was a political analysis of sexuality were able to make a positive choice to be a lesbian. I believed then, and I believe now, that if bisexual women had an ounce of sexual politics, they would stop sleeping with men.
This opinion did not exactly endear her to bisexual women, one of whom accused her of curtailing her autonomy:
Removing the autonomy to choose who one can and cannot f.... is not feminism and it never can be.
And here is Julie Bindel making the same point about not loving the enemy:
The reason why so many of the new-wave feminists bleat on (and on) about including men in feminism is because so many of them are unthinkingly heterosexual. Women are the only oppressed group that is required to love their oppressor, sexually and every other way.
Again, that makes sense if you support views like the following ones, as quoted approvingly by Julie Bindel:
Finn Mackay, a feminist activist and academic has organised the Reclaim the Night march in London for the past six years, believes that men do have a role to play within feminism, but — it is not coming along to meetings and taking part in the decision-making process. “They can stop rape by not raping, and bring the sex industry to its knees by not paying for sex,” says MacKay, without a trace of irony. “Oppression doesn’t just happen to women like bad weather. Men as a group systematically oppress and exploit women, and feminism is the political movement to challenge and change that.”
If that's what you believe, then why not be a radical lesbian separatist feminist? And why not believe that marriage, as a patriarchal institution, should be abolished:
I absolutely agree that fighting for the rights for same-sex marriage is going too far. I would outlaw marriage for everyone, including heterosexuals...
There are two paths here. One path is to accept the claims of feminist patriarchy theory - in which case it makes sense for women to avoid friendly relations with men. The other path is to scrutinise these claims. Is it really true that men as a class have acted to perpetrate violence and oppression on women? Couldn't the very opposite claim be argued for? That men as a class have acted to protect women from violence and to work to improve the circumstances of women?
In Western societies there was traditionally a very strong ethos amongst men that it was dishonourable to commit an act of violence toward women. So if men acted as a class it was to repudiate violence against women rather than to commit it.
Similarly, there was a strong ethos amongst men that they should work hard to support their wives and families. Many tens of millions of men have laboured on behalf of their families when they could have had easier lives living for themselves alone.
There is a much more positive reading of the masculine than the one normally pursued by feminists like Julie Bindel - and it's a reading that permits women to openly embrace their heterosexuality.