I have so many Italians friends here in Canada... all they care is football (soccer). tennis is an individual sport ... I mean look at it, how come a small poor Balkan country like Serbia has the world #1 and another guy (Tipsy) who is what #8... no tennis history, no nothing ... that's what I love about tennis, you are pretty much on your own, no matter where you you are coming from ...
I'd be willing to bet that there are more tennis players in italy per capita than serbia. There may be a grain of truth in your premise however. I consider russia to be a country which emphasizes individual sports more than team sports (exception being hockey). The result is that they dominate the olympics etc.
So, it's possible that one could argue that italians just suck
at tennis. Stranger realities exist in the universe. Politically correct? Nope. But who said the truth doesn't hurt sometimes?