I used to live in Rome. My favourite gelato place is west of Piazza Navona called Gelateria Quinto. Can’t say it’s the best, I’ve only tried about 20 different places in Rome and about 40 places across the country. But Quinto gives me fond memories. Friendly staff.
Actually, this article is a inaccurate. There are 2 types of pistachio gelato - one made with pistachios, another made with candied pistachios. The ones made with candied pistachios gives a brighter green and more aroma. They are actually more authentic, much like dried spaghetti is more popular than fresh ones.
An authentic gelateria would always have Zuppa Inglese, and they use a scraper rather than a scoop.
The problem with the article is confusing authenticity and quality ingredients with taste. You like what you like and there is nothing wrong with it.
My suggestion about gelato is to observe the scraping marks left on the tub. High fat ones will leave almost no ripples, high fruit content ones will have some ripples but never as much as with American ice-cream. Remember what you like, and pay attention when they scoop it will help you pick it in the future.