Yes I agree, here in Belgium we all understood the issue.
They Hire for summer, they made the season with you, in some flights they have the return on the investment, if they keep you on the company during winter then you cost too much so they prefer to kick you out, hire a new cadets, no salary during winter season (type rating phase), you are ready for next season, well its a good deal there financial dept found.
Someone have to talk with the Belgian Ministry of Employment.