I see it a bit differently. There is no reason why tourism shouldn't be the main industry and source of employment in Venice. When you are consistently ranked the #1 most beautiful city in the world, there will be tourism. (
http://www.cntraveler.com/galleries/...in-the-world/1
http://www.themeshnews.com/top-10-mo...ld-2016/<br /> http://topxbestlist.com/most-beautiful-cities/ https://lifestyle9.org/top-10-beautiful-cities-world/
Venice welcomes tourists. However, it has disdain for invasive, destructive tourism. The First three pictures below are people disgorged from cruise ships. I don't know why people would want to be there and visit Venice that way, but I assure you they aren't helping the economy, they are costing the city money. The docking and port fees from cruise ships all goes to Rome. Then, Rome sends some small amount back, and it is not even enough to pick up the trash, or to restore the wear and tear that these people cause. These masses of people might buy a trinket or two, or maybe even a T-shirt, but they don't bring any profit to the city.
Even then, Venice had quite a bit of money, until Project Moses, the gates at the entrance of the bay that was planned in 1987 to protect the city from flooding. It's still not functional, has already cost almost 6 billion euros, way over initial estimates. Almost all of Venice's money went to this supposedly brief project, instead of schools, transportation, infrastructure. It is still nowhere near ready. The reason? The Mayor and the city leadership skimmed most of the money off, with the help of the Mafia. They were all sentenced to jail, meaning house arrest in their mansions. There is a rule in Italy that after a certain age, you can't be put in jail, so they are all out. That's why Berlusconi didn't go to jail despite convictions for prostitution, tax fraud, and sex with a minor a few years ago.
As you mentioned, the university Ca'Foscari was recently ranked one of the best in the world in science, research, economics, and other areas. The economy of the whole northern rim of Italy is very strong, on par with Germany and England. Venice is just getting skunked by unbridled tourism.
Look at this 40 second video. A tourist actually jumped off of a bridge into the Grand Canal started paddle boarding.
Venezia, turista giapponese si tuffa con tavola da surf nel Canal Grande - YouTube
A few months ago a tourist jumped off of the Rialto Bridge, going for a swim. Unfortunately, he landed on the window of a motor boat. He spent the next three months in the hospital, then died. This summer a family of about ten gathered right in the middle of St. Mark Square with a bunch of pots and pans, started a fire, and started cooking curry. When told to stop, they said they were just trying to save money.
During the summer, you literally cannot walk over the Rialto Bridge. People taking selfies have it packed. You can't even cross regular neighborhood bridges because tourists are sitting down on it shoulder to shoulder, eating sandwiches.
Now, there are short term rentals avoiding taxes, and tearing neighborhoods apart. Venice is finally a plan to finally manage its mass tourism, and everyone hopes it comes to pass.It just started using its first electric vaporetto and is replacing 54 more to cut down on the pollution in the lagoon, largely caused by cruise ships. They just put a list of 500 ideas to restructure the city, hopefully some will be fruitful. If Venice just carefully curated visiting the city and managed it, tourism wouldn't be a problem, and would probably be highly profitable instead of destructive. It is estimated that 50% of the crowds you see in the street are there for the day, touring in a group, and not spending money. They are not the base of the Venetian economy. Severely regulating cruise ships and AirBnb would do much to make Venetians feel that it is reasonable to stay. I actually have to walk through those crowds to get where I'm going, and so do they.