Even with the raised fee, people are still trading at OkCoin and BTCC with huge volume compared to other exchanges.
It's not exactly "huge" anymore, but still BTCC and OkCoin
are among the market leaders.
The reason is easy: There should be plenty of whales that are not from China and were trading at Chinese exchanges benefitting from the zero-fee policy. According to the theory of the path dependence (one can call it simply "inertia") most of them will stay there for a while, but at some moment they may decide to change back to "western" exchanges.
I expect the volume going down slowly in the near future at the Chinese exchanges, because for non-Chinese traders there should be more advantages to use exchanges near the country of residence (e.g. easier fiat deposits and withdrawals) and the regulatory environment in China is still somewhat "unstable".
I don't find huobi in your second pie chart, is there any reason for that?
Huobi seems to have had API problems (they didn't show up at Bitcoinwisdom and Bitcoinity the last few days). Perhaps someone has more exact information, but their website seems to be working.