I raised my eyebrow at this for a second, so to save someone else the Google search: the Student Loan Company isn't a private corporation, but rather a UK government organization: https://www.gov.uk/government/organisations/student-loans-co...
The question is, what system would avoid this perverse incentive? A graduate tax would have the same problem. Free tuition shifts the burden to every taxpayer unfairly. Maybe another repayment scheme, but that would disproportionately harm poorer students.
To tell you the truth, I'm not sure what tools a creditor has to pursue a debtor who has left the country in general...