Pontification aside, it may be better to take the loan out in your home country and transfer the funds here. The loan sharks here will probably not touch your case and if they do, they'll be prepared to break a few legs if things go bad.
Surely, between your family and her family back home and some assets in those countries you guys can scrape together the funds required?
Another option might be to find someone local who is sympathetic and perhaps get them to sponsor the wife's visa (not sure if this is even feasible ... check the IMMD website or email them and ask if a local sponsor can help).
If not, then perhaps best to accept that life is not fair and make the best of it.
Would not recommend going down the loan shark route here in HK - you'll be swamped with very high interest rates and fees. These guys lend to make serious amounts of money... not to make your life better.