Although PSW is abolished, Tier-2 visa becomes much easier to obtain at the moment. I guess your friend is a current student at LSE and ABN AMRO does not have a sponsor license now. Most big banks have got a license and a lot of quota to sponsor international students, even in the old days that Tier-2 visa was difficult to apply for. If anyone wants to find a job in the large institutions in the UK, the difficulty is actually less now.
My theory is that a lot of Chinese students do not even attempt to stay in the UK, or try a bit and then give up after some difficult time. Actually many like to return to the HK or mainland. Some may prefer the UK, but are intimidated by some crazy rumors about the difficulty. From what I have seen, those who are very committed to stay in the UK have got a good chance to make it if they attend one of the top schools.