Sorry, I don't find it funny!

Why is it when a film depicts a character going into a shop or supermarket, that person inevitably does a bit of shoplifting? Moreover, in every case the deed is portrayed as something we should chuckle or laugh out loud at, or even applaud when the thief manages to leave without being detected or escapes a following pursuit. I grimace when I hear the audience give the 'desired' reaction, equivalent to "Ha ha, what a lark! How cool!" Don't they and the film-makers ever entertain the thought that thieving is wrong? I'm prepared to accept that there may be life-and-death situations where robbery is the only means to prevent starvation, but this is hardly ever or never the case in films. At the risk of sounding really goody-goody, I've never in my life stolen any article, certainly not from shops, not even in the days of fooling around as a kid. Could this be one of the positive results of having had a rigid Catholic education? Maybe, but I doubt it - in the U.K. Roman Catholics represent a disproportionately high percentage of the prison population, and have done so for decades.
I raise the subject because I've just seen an otherwise rather good new Australian film, 'Samson & Delilah', which includes such a scene. In fact the only single film I can recall off the top of my head where shoplifting was depicted as undesirable, was in another Aussie film, 'Muriel's Wedding', when Muriel's mother, beset with mental health problems, absent-mindedly takes an item from a shelf without paying for it. She is nabbed but returned to her home by the police, excused on this occasion when her mental problems become evident. But she is portrayed as a rather pathetic and tragic figure, a far cry from the 'bravado' of a gutsy 'true heroically successful thief.
Maybe I'm just a reactionary fuddy-duddy, and stealing is nowadays regarded as a bit of harmless fun. But nevertheless it does disturb me that others think the whole subject is so light-hearted it can be simply laughed off. Or is it a case of me not 'changing with the times'?