Okay. Let's break that down.

I think that reasoning is a little on the torturous side.

Have you ever read any supreme court (US, European or other) court rulings?

They are, and have to be by their very nature, tortuous. Much, [http://hudoc.echr.coe.int/sites/eng/pages/search.aspx?i=001-67482#{"itemid":"001-67482"}|much], much more tortuous and convoluted that my brief paraphrase.

In this particular case,

About this specific case ...

I would think

You've reach a judgment ...

it more likely

Based on some statistical probabilities ...

for a reader to assume

that 'all readers'? or 'an average reader'? a 'majority of readers'?

And is that male readers -- you have insight to the minds of all men -- or female readers -- you have insight to the minds of all women -- or both?

And are you assuming those readers will make the same assumptions as you? Or maybe you are suggesting they should?

that the attack is against the perceived behaviour

In order for the readers to assume a perception (by the writer) of a third party group; they would have to also perceive that behaviour of them; or be aware that the perception of that behaviour by that third party group is widely held.

Either way; if the perception is so widely held then it is not an individual targeting the group in an attempt to disseminate a malevolence; but rather a joke targeted at a common (perhaps, mis)perception. Common fodder for humour in all walks of life and target groups.

of "all feminists"

So, you are assuming, that all readers will assume some thing about all feminists.

You are, of course, entitled to hold your opionion, but you'd best be very circumspect in levying accusations based upon it.

You haven't and aren't; but the same applies to anyone else basing accusations, upon such assumptions of many other's assumptions; about many others.

than that it have anything to do with the philosophy.

Feminism is a philosophy, and actually many different (flavours of) philosophies, and to ignore when drawing conclusions related to it, is to ignore reality.

Sexism can be defined in terms of equality of treatment between the sexes; but feminism is a fuzzier, malleable, whatever the proponent chooses to read into it affair, and impossible to adequately define..