First off: This has nothing to do with being a woman. As both a female and a feminist, I'd love to see a woman in office, but I'm not ready for this woman in office. You can bet that Bernie Sanders will be getting my vote in the primaries over Hillary, and here's why.
1. Her Past Voting Decisions
Hillary Clinton voted in favor of the Iraqi War, the Patriot Act of 2001, and the 2006 decision to build a fence between the United States and Mexico. She supported SOPA's internet censorship and the NDAA's power to detain American citizens without trial. She voted to bail out Wall Street, voted to bomb Syria, and didn't support the federal recognition of same-sex marriages prior to announcing her campaign for president. Of course, now that she's a candidate for the 2016 Presidential Election, she's gone back on most of these decisions in order to win the support of Democrats across the nation.
2. The Cost (And Source) Of Her Campaign
Since her presidential campaign is one of the longer ones (compared to her Democratic and Republican opponents), she's already spent a total of $18,200, compared to Bernie Sanders mere $3,000 campaign. Most of her financial support has been garnered from large corporations, the top three being Citigroup Inc, Goldman Sachs, and DLA Piper. Politifact shared a chart that compared Clinton's and Bernie Sander's top ten sponsors, and all of Clinton's are from businesses, the media, or banks, compared to Sanders', which is entirely funded by labor unions.
3. Public Opinion
According to a Franklin/Pierce University/Boston Herald poll, only 35% of Democrats report actual support for Clinton, 51% could potentially support her, but they're not enthusiastic about her candidacy, and 13% outright don't support her. Why? Her voting history doesn't align with her current platform (her approach to economics is very moderate, if not slightly conservative for a Democratic candidate), and her funding doesn't support her message of voting for the public.
4. Trust
We don't need to get into her private e-mail scandal or Benghazi... But when you're in the public eye and get caught, doesn't that suggest something about her truth worthiness? A poll from Quinnipiac University asked voters in Colorado, Iowa, and Virginia (three major swing states) on their opinion on Clinton's trustworthiness, and each state reported that over 50% of their votes find Hillary dishonest and hard to trust... especially when it comes to being president.
5. Public Eye
Hillary's been in the public, political sphere long enough to catch people's attention, which may have been a good thing when she was First Lady and Secretary of State, but isn't so much now. Older voters remember her past decisions and mistakes, and they aren't likely to forget when they're voting. Other candidates who are relatively new to the attention from the whole country may have a little advantage over Clinton, who has to win over the neutral crowd... and those who have already decided that they don't like her, which is a tough enough sell as is.