Answer:
Modernity
One reason that Arab youth are abandoning classical Arabic is due to the changing times. English keeps infiltrating more and more societies as the world language so Arabic youth tend to use it more when texting each other or using social media because it means that they can be understood by more people than just people who can speak Arabic.
Schooling system
A significant number of schools, even in Arab countries, offer their classes in foreign languages such as English and French. This has led to Arab youth learning more of those languages and less of classical Arabic which they can only pick up from family or interactions outside school.
The need to get Jobs
With the world increasingly moving towards convergence as a global village, most jobs require that prospective staff be able to speak a foreign language such as English that would enable them communicate with foreigners.
As a result, Arab youth find themselves communicating in English more in order to qualify for jobs.
