Americal Pilots association have a series of videos relating to the perceived pilots shortage, and one piece of it is especially relevant to this discussion. It shows with data and statistics why less students in the states are choosing the pilot profession.
Although the video is more relevant to the American market, I assume the same principles regarding return on investment will apply to the European market.
It seems less and less people in the states are choosing to join this profession, and it would be interesting to know the same is true about Europe.