"If ... they believe the shroud is a medieval forgery, I call on them to repeat the exercise, and create something similar today," he says...
It's been done, see for example the Reuters 2009 article.
More on the subject here.

When judging an event like this you need to contextualize it.
Italy is a very weird place, different from the other European countries. In Italy the bishops actually can veto or modify a law, actively lobbying the political power.
There has been a long string of attacks against science, the last was against the possibility to safely use assisted reproductive technology (you are forced to be implanted with all the embryos, no way to control the healthiness of each single embryo or their number!)

When the pope speaks, it's not a mere matter of religion. It's a political issue.