Shorter Oxford English Dictionary defintions of 'cosy':
Positive: Of a person: comfortably sheltered, snug; of a place: sheltered, warm and comfortable, inviting; of a person or thing: warmly intimiate or friendly.
Derogatory: complacent, smug, unadventurous, parochial.
I have always loved, sought-out cosy places; especially in cafes, pubs, libraries, and even in the countryside (niches in old graveyards, the edges of woodland etc).
The love of cosy corners used to be characteristic of the English - and the best English architecture is often replete with cosiness: think of traditional college buildings.
Yet in modern life it is almost impossible to find a cosy corner anywhere - all is harsh light, sharp angles, hard surfaces. Modern architecture can be cramped but never cosy.
Over the century from 1850 to 1950 the English intellectual elite swung all the way around from the positive to the negative attitude towards cosy; and they imposed their adolescent disdain for cosiness on everybody else.
I mean the secular intellectual attitude which sees anything 'cosy' as complacent, smug, unadventurous, parochial - and since the secular mandarinate rose to dominance they have been eliminating cosiness from the modern environment, whether we like it or not (mostly not).
But in my book, to be anti-cosy is to be guilt-riddled, submissive to power, cosmopolitan, restless, distractable, empty-headed. To be anti-cosy is to be the kind of loud-mouth or show off who enjoys sitting in the middle of an open-plan office or canteen engaged in publicly broadcast discussions on their mobile phone.
I have been reading the Harry Potter books to accompany my daughter: clearly one reason for their success is their depiction of Hogwarts in terms of being an epitome of old fashioned English cosiness: soft chairs beside open fires, old libraries with study corners, dark pubs with semi-enclosed circles of chairs, trains with corridors and private compartments, schools with small, enclosed classrooms...
Only adolescents and secular intellectuals (who remain emotional adolescents) despise cosiness. Decent people treasure it.