This is the standard view, and in the film it is made quite clear that this is a fall from grace, from the simplicity of the town in the early minutes of the film.
James Stewart in It's a Wonderful Life finds himself in a lurid and corrupt parallel version of the Norman Rockwellish city of Bedford Falls. Hookers flaunt themselves where dry goods merchants once traded; the Italians, sanitised and jolly in the real town, in the parallel one border on mafiosi. it is a very Mumford-ish film.
The history of the anti-city lament is interesting in itself, and as old as the the city and, since it is history, changes through the ages. The city is immoral and corrupting while the country is inherently moral and salutary. Raymond Williams traces suspicion of the wickedness of the city from very early on in the history of literature. Specifically London is grumbled about as early as 1177, hardly a Sodom, more like a small market town; (estimated population at the time, 25.000): "whatever evil or malicious thing you will find in that city" (our provincial friend Richard of Devizes again.)
Thomas Jefferson considered very early New York to be a "cloacina of all the depravities of human nature"; and this at a time when Manhattan was a collection of modest residential homes flanking a bowling green.
Moralist indignation does not flag. Ruskin's diatribe is almost comically Old Testament:
"Loathsome centres of fornication and covertousness….the smoke of their sin going in to the face of heaven like the furnace of Sodom and the pollution of it rotting and raging the bones and souls of the peasant people around them."
Now it is social reformers, hygienists, political radicals who condemn the city. With Marx and Engels' dark reports from the manufacturing towns, and later writers such as Booth and Beatrice Webb, the badness of the city became profoundly politicised; indeed the city could be seen as a summation of everything that was wrong with capitalism. Political change, for the utopian socialists anyway, rather than for the Marxist, could most dramatically be expressed in the dismantling of the city. In News from Nowhere the hero wakes up (after falling asleep in the horrors of late Victorian capital) to find that he is in a London that is "small and clean and green", a sort of Legoland London achieved after a socialist revolution triggered by a massacre in Trafalgar Square. A London "small and clean and green"? No thank you.