Yes, work arounds are needed because you’re right that sites are being loved to death. But it’s not from a couple cruise ships docked an hour away.
We took a wonderful evening stroll of Rome two Decembers ago, led by a great Walks of Italy guide. Rome was pretty busy, but it was the last Saturday before Christmas and she remarked it was mostly locals out shopping. This did lead to a discussion of tourists. She has been a tour guide in Rome for over 20 years. She said Rome in summer has become unbearable and she places the blame directly on the influx of passengers from cruise ships. It's not "a couple of cruise ships", I've seen aerial photos of Civitavecchia where I counted 12 cruise ships in port at one time. Let's say they average 2500 passengers each, that would be 30,000 passengers, most of whom will be traveling for a day trip to Rome.
She said it's not only quality, but quantity. The day trippers are under time pressure and she says they can get pretty aggressive. I haven't been on a big cruise ship, but based on my experiences with passengers on a river cruise and how they act at port, they are not the kind of people I want to spend time with. People who find taking a cruise on a big cruise ship have a different traveling philosophy than mine.
Ports are realizing that cruise ships have a negative economic impact. The passengers use resources but they don't add hardly anything to the economy of the port. Day trippers don't spend money on accommodations and their food purchases are minimal compared to tourists who stay for a few days.
Luckily there are alternatives. We travel during the shoulder and off seasons. We alternate between the usual suspects (Rome, Florence, London, Paris) and smaller, out of the way places.
Read these for a better understanding of tourism in general and cruise ships in particular:
From the BBC
From Green Global Travel
From the Guardian
From the Sun.
From the Huffington Post
I like to travel, but I'm aware that there is a growing problem related to travel. It is no better in some areas of the US, especially at the more popular national parks. I've been going to Florida since I was a little boy. 30 years ago we discovered a nice little area off 30a called Seaside. That entire area has been ruined by uncontrolled growth. We no longer go there. It is too painful.