>The elephant in the room is that in quite a few European countries (such as Italy, Germany) it's free, hence the well-known phenomenon of the "eternal student".
You are simplifying it a tad bit too much.
In Italy Univesity course is not "free", it has a low cost (taxes and fees + books), but - unless you (with your parents) already live in the city where the university is, there are transfer/lodgement costs.
There was an article just the other day on the Corriere della Sera about the situation, I assume you can read Italian, otherwise it is not that bad via Google translate:
http://www.corriere.it/dataroom-milena-gabanelli/quanto-cost...
And - with the exception of very few specific and "technical" courses the issue is that once you have spent these 15.000-45.000 Euro you are not going to receive - if you find a job - an increased wage when compared to someone without a degree or with an undergraduate degree.
Of course the main underlying reason is that there is a high unemployment rate, and "on the market" an "average" degree has not much increased value.
Possibly something similar happens for CS, firms have "basic" CS degree as a requirement but do not value much an additional Master.