They leave nasty bruises and spread diseases. It seems humankind is successful in getting rid of other species - then why not mosquitoes?
Do they make any vital contribution to the ecosystem? I have never met anyone who appreciates them, so if they don't have a specific purpose (besides nuisance, itchiness and infection), I suggest that we unite to put an end to their stinging. A global movement against mosquitoes - yes, please.
I will still have to consider how, though.