My ability to read between the lines tells me this is not a unilateral China action, but in conjunction with various globalization treaties. In the past 4-5 years, the USA has been making it more and more difficult to move assets out of the country and attaching all ID documents to a central database so that your tax records are connected to your passport, etc.
Making it tougher to come to China, especially for people with legal problems, benefits both sides, but also goes along with statements from the treaty meetings of the past 10-15 years, as well as books and articles from the players of those meetings, that getting out of the developed countries that are being de-industrialized is meant to become more and more difficult. See Millennium; Winners and Losers in the Coming Order
Probably several reasons, and one of them could be that having large numbers of people who have concepts of human rights, workers' rights, property rghts, etc. coming to the slave-worker corporate globalization heaven of the middle kingdom might not be conducive to maintaining the status quo over here.