Or more subtly cynical: it's a way to boost net wages without actually increasing salaries. This is a real problem in the PRC, where the enormous trade surplus has left an artificially depressed local currency. Workers are being paid much less than they should/would be in an unrestricted exchange environment. The whole point of the managed exchange rate is to keep salaries low of course (and thus preserve that trade surplus), so there's no doubt pressure on executives from boths sides: underpaid workers and government regulators trying to avoid a wage explosion.
But I honestly don't see what's the problem with such a technique. Of course it would be better for the employees to get a raise. But it would certainly be worse to get nothing at all.
If they get something (money) and the company gets something (loyalty), it's a win-win. Could be better for the employees, I agree, but that's a bit unrealistic these days for the reasons you mention.
