I think it all comes down to Hamlet's perspective on this particular issue. He has been so let down by his mother's actions that he attributes her frailty (unfairly) to all women, which ends up as the reason he ia capable of pushing aside his feelings for Ophelia. I do not believe Shakespeare, as the playwrite, was putting this out there as his actual belief regarding women. He wrote some very powerful female parts, especially given the constraints his time period placed on him.
Sounds like a plan. So, which side do you wish to take? The idea that Hamlet is wrong, and women are in no way the epitome of frailty? Or, do you wish to play the ever popular devil's advocate and pursue the reasons why Hamlet may be right, however politically incorrect it may sound today?
I'll start by pointing out the time period during which this play was written. In several of the Bard's works, women are objectified and seen as overly emotional, mentally unstable beings that look to men for protection and guidance. While such plays as "A Midsummer Night's Dream" do allow audiences a chance to see women as clear articulators of their passions and emotions, they also serve to perpetuate a notion that women are consumed by their passions, thus acting irrationally as a result of them. One can hardly say that Helena seemed all that "with it" during certain parts of the play.
Consider also Caesar's wife, who was willing to cut her own thigh to show that she could take the pain just as a man could. Later, she swallowed coals; hardly a rational thing to do. But, doesn't the very idea that she'd have to cut herself to prove her "manliness" prove that women were seen as intrinsically weak and frail during the time period?
Let's hear from someone else...
I think that Hamlet is frusterated (of coarse he is) because his mother jumped to the next man she saw like it was no big deal. It was all about perception, he saw his mother love his father and when his father died she ran to the next available man to be king within 2months. To him she looked like she didn't love her husband enough to morn and greeve over his death but to find another suiter for the kingdom, like the kingdom mattered more than the king.