You obviously either didn't read the article, or didn't understand it!
The whole idea of this system is that they fingerprint you TWICE.
Once at check-in when they associate this fingerprint with your bag.
The second time _at boarding_ so that they know that the person who checked the bag in is actually on the plane.
I have never been on a plane where you have to manually open any doors after the boarding check.
You are right that there are a number of things that you touch after boarding, but the only one that you _have to_ touch is the seat belt and unless you try every seat on the plane this will not have been contaminated by every other passenger. Also you have the choice as to how you hold the belt when doing it and can even wear gloves if you are fussy (as I would probably be at times when I know the norovirus is spreading widely).
What they are doing here is forcing cross-contamination of all passengers!
Oh, and before you suggest it, those alcohol wipes that get used for things like injections tend not to work on norovirus as it does not have a lipid envelope .