if it where just passing comment on somebody purely due to behaviour that is criminal like many of the things that have been mentioned in other posts under the term antisocial behaviour then you are not sneering at a person its stating you feel criminal behaviour is wrong. but if that where genuinly the case would you really use the word chav or would you say antisocial.and could it equally apply to someone who was say a lord.
why do we have things that are deamed to be chav wear, chav hair, chav names we even have chav jobs and chav children.a huge ammount of people may never have seen any actual aspect of these peoples behaviour they just make a judgement based on area lived in/school attended this that are compleatly dependant on income level. and it is very rarely used just as a comment on type of dress like saying goth. if you live in a poor area you are very likly to get called a chav as an insult but you are unlikly to have quite the same venom applied if you like to wear black or want to die your hair green.
if you saw me in my place of work you may look at me and assume 'chav' you would be highly unlikly to think it if you saw me dressed the same way in a different enviroment if i saw you in my home area and i were so inclined (im not) i may look at you and think chav. both of us would probally be very wrong.
no matter how high up the ladder you are or think you are somebody will allways look down on you because they think they are better and 99% of the time we totally accept this as unacceptable or just compleate stupidity its a bit of a joke on the person doing it like mrs bucket on keeping up apperances. its only when it comes to the word chav or commen that so many people think its ok.
you personally may only use the word to describe criminal behaviour or bad manors but so many people dont so many people use it as a insulting descriptive word to describe anybody who lives or did live on an estate they lump everybody into the same group and use it to put the entire group down.games like this one just reinforce that attitude.
as a child i had an aunty who was fairly unplesant she would have looked at a perfectly decent law abiding person who did unskilled or skilled manual work and anything they did would have been "oh so very working class" said in a unplesant way anybody was up the ladder would have been "dreadfully middle class" but anybody who tried to move upwards would have been getting ideas above their station.if chav was around she would have been delighted to band that about and would use it to describe all those people,i never enjoyed her company she was nasty