I'll assume for the moment that women's suffrage is a good thing. It's still possible to do good things for the wrong reasons.
If you ask your typical leftist or liberal what the reason was for women's suffrage, they'll say "equality" - precisely the same reason they'll give for gay marriage, income redistribution, affirmative action, capitulation to Islam, multiculturalism, and all the various feminist abuses you've complained about in this entry.
But what do they mean by "equality"? Do they mean that women are, in general, equally prone to being politically and economically informed as men? Or perhaps liberals thought that womens' tendency to be less politically informed was simply a result of them not being allowed to vote, and that letting them vote would remedy that situation? If so, they were mistaken. Did they think that women are, in general, equally rational and capable of putting aside their emotions when considering abstract political issues as men? If so, again, they were mistaken. The greater emotionality is intrinsic to women (they couldn't perform the essential role that men can't - nurturing - without it).
Why do you think it is that women were not included in suffrage in the first place? Was it because of male oppression? Was it because our Founding Fathers were sexist jerks who didn't believe in equality?
In my opinion, no. It was primarily the result of the fact that women typically aren't naturally as interested in, or informed about, abstract political issues as men are, as demonstrated in that link above. Nearly all of the political philosophy and theory, rhetoric, political passion, energy, and manpower driving the American Revolution came from men, so it made perfect sense that they placed the responsibility of safeguarding what they had worked for on themselves once they had won it. That women weren't also placed in charge of guarding it at first was simply a reflection of the fact that, with few exceptions, they weren't the ones who had created and fought for it, intellectually or physically.
Later expanding the franchise to women was an act of generosity, not the overdue recognition of some natural and intrinsic political equality that had always existed but which had been suppressed by selfish and brutish patriarchal sexists. A person expecting some sort of material parity between the sexes to manifest itself in the wake of womens' suffrage would be sorely disappointed, and would likely move on to the next mad scheme to achieve it.
So it's not that women's suffrage itself necessarily leads to the many abuses of feminism we see today. It's the rationale typically behind it. If your rationale for suffrage is "equality", then you need to think hard about what you mean by that. It could be that you're using the same logic that has been used to justify all the atrocities of feminism, but that you just haven't (out of basic sanity) been willing to push it as far as they have.