It used to save them money to have people on bases. Now, with all the lawyers and accountants and payroll companies and administration of based employees and unavoidable bargaining meetings and extra corporate and payroll taxes, not to mention the reduced productivity, waste of time and waste of money and waste of resources.....not so much.
Of course, this doesn't apply to iCadets, who cost nothing to keep in HKG (10K/month, maybe 20 or 30 soon...still nothing) where they are far more productive and consistently available for extra work.