School searched for illegals

According to Yomiuri Shimbun,
the Tokyo Regional Immigration Bureau searched a vocational school in Musashino, western Tokyo, on Friday after learning that 140 of its overseas students overstayed their visas last year. They suspects the students worked illegally while they were registered as vocational students and still maybe doing so.
The Tokyo bureau conducted a trial investigation last month on 10 schools in the metropolitan area. The student body of one was entirely Chinese, while another had only four Japanese students out of 74. Eight of the schools padded attendance records or did not hold classes.

文部科学省は、職業学校では全学生の半数以上が日本人でなければならないというガイドラインを設けているが、なぜそこまで外国人学生の数を規制する必要があるのか？日本でさまざまな職業技術を学びたいとやってくる学生が、なぜその可能性を制限されなければならないのか？条件が厳しく、就労ビザが得られないことが、彼らがこういった学校に籍を置いてこっそり働かざるを得ない状況を生み出しているのではないのか？