i think it does matter.
it's about how society views women (and other races, religions etc). yes, there will always be offensive views out there but it's our right to tell them they're not on and that society, as a whole, does not find this funny.
would you accept someone wearing one of those t shirts on the desk next to you? or making comments along the same lines? of course not, you'd tell them it was offensive. freedom of speech gives them the right to spout but it gives the rest of us the right to tell them they're offensive.
we have to challenge this stuff. and all the other 'little' stuff. because it does matter. if t's ok to laugh at women or muslims cos they don't matter and no body cares about them or what they think or how they feel then women/muslims/whoever start to become 'other' and we know where that can lead.