I hear you. Unless there's some sort of crowd control, I can't see that the fee will deter anyone at all. It could be sort of pricey for a daytripping family of, say, 2 adults and 4 kids over age 6, but still. Policing this thing, what with the list of exemptions, will be interesting.
The per-night accommodation tourist tax has been around a long time, and we've paid it in other locations in Italy so that doesn't bother me. Heck, some cities/accommodations here in the U.S. nickel-dime to death with taxes and fees: Mandatory per-night "resort" fees, parking fees, facility fees, state + county + city taxes.... I HATE resort fees as they can be really high - as much as $30 - $45 a night - for stuff like spas, pools and fitness facilities that we don't want or need; the first dealbreaker when looking for an accommodation. Haven't had to deal with that nonsense yet in Italy, thank goodness.
https://www.italyvacations.com/tourist-city-taxes-italy