In the 18th century tea wasn't really a thing in Italy, only coffee, so much so that a Frenchwoman visiting an Italian castrato in the 1700s took the time to note in the letter that his was the first house where she'd not only been offered tea, but had a right decent cuppa. (This was a guy called Senesino, who was a real Anglophile and had a whole house in Italy full of English stuff, so he was special.) I'm given to understand tea still isn't a big part of the Italian culinary scene.
So why didn't the Italians, compared to neighboring European nations who love the stuff, take a liking to tea? Did they simply not have cheap or easy enough access to it?
edit: if I'm wrong and the Italians are not unique for not drinking tea please explain it in full. Why did some European nations take to tea while others did not?
I can't speak so much for the 18th century, but generally coffee came first to Europe. Interestingly, and somewhat ironically, England had one of the greatest passions for coffee in all of Europe in the second half of the 17th century. One example would be the British MP from the 1670s Samuel Pepys, who kept a diary. He mentions coffee several times, saying "my Lady having made us drink our morning draft there of several wines, but I drank: nothing but some of her coffee, which was poorly made, with a little sugar in it. Thence to the ‘Change a great while, and had good discourse with Captain Cocke at the Coffee-house about a Dutch warr".
Pepys often refers to coffee-houses as a regular meeting place, and very rarely discusses tea, with only a few exceptions such as this one:afterwards I did send for a cup of tee (a China drink) of which I never had drank before, and went away.
Coffee was more easily accessible, being imported from the relatively nearby Ottoman empire versus tea having to travel all the way from China and India. It wasn't until the serious colonisation and general domination of the Indian Ocean and surroundings by Europeans that tea began to gain ground. So, my guess to answer your question, would be that since Italy never really got a slice of the colonial pie, they never had an incentive to switch, since both drinks had to be imported. On top of that, their proximity to the Ottoman empire made coffee importation a relatively straightforward affair. In fact, Venetians were among the earliest European vendors of coffee. I know this doesn't really answer your question, but hopefully it'll shed some light on the reason behind Italy's missing the tea bandwagon
couple other links on coffee:
http://ineedcoffee.com/before-there-was-tea-there-was-coffee/