Thanks for posting that article. I believe the same one was posted here about a week ago, but it's good to keep this in the discussion. I'm not sure where that picture was taken but the only place I can remember that has galvanized steel walkways is the Manarola end of the Via dell' Amore. It's not likely that large crowds would have been using that one in the last three years, so this may be an old picture?
I wish I knew what the answer was. I suspect they will have to work with the cruise ship firms on this one, as that area simply can't absorb multi-thousands of passengers in the same day. The majority of passengers probably take one of the excursions offered by the cruise lines, so one possibility might be to have a quota on how many people they bring to the Cinque Terre on each port visit. If there are several ships in port on the same day, that would have to be co-ordinated between all the lines. There are lots of other locations for cruise passengers to visit such as Florence, Pisa or wherever so some of them could be channeled in that direction. It would also help to have some co-ordination with the major tour companies that bring groups in for the day such as Trafalgar, Globus, Tauck, etc. I don't include RS groups in this as they're much smaller in size, they usually stay there rather than being day-trippers, and they also sometimes stay in alternate locations such as Levanto so the impact from RS groups is minimal.
I agree completely with your last paragraph. It's not necessary to avoid the area, but be aware of the situation and plan accordingly. I've been developing "coping strategies" over the last few years, and I'm not too concerned about the crowds as they have minimal impact on my touring. However, I should add that I try to avoid Vernazza in the day time. I was back there again in September and even this mob involved in a fierce argument at the Monterosso station didn't bother me (they weren't from the cruise ships, but rather German and Austrian tour groups). The entrance to the platforms was plugged solid and while I could have used an alternate entrance, I decided to go have a cup of coffee and visit with other travellers instead. I'm never in a big hurry when I'm there.