Another reason is the proliferation of pirated copies of Windows.
Life is extremely hard for Linux users. Less so for OS X, but occasionally you still need to dual boot.
In January 1999, RFC 2246 (128 bit SSL) was finalized and permitted for export, but by then SEED was already entrenched. It's only now that smartphones are starting to become popular that they're trying to change things: http://www.koreatimes.co.kr/www/news/tech/2010/09/133_73601....
You can read Gen Kanai's post about it on the Mozilla Asia blog for more info: http://blog.mozilla.com/gen/2007/02/27/the-cost-of-monocultu...
People from Mozilla China have recently pointed out to me the crypto-related issues in China. My understanding is that you can make Firefox do what you need for Chinese banking but it requires unintuitive configuration and/or hard-to-get drivers. I am hoping that sometime this year we will make improvements to make smartcards plug-and-play on platforms (like Windows) that support it. This will be a nice benefit not only for Chinese users, but also for any other smartcard users.
I don't know enough of the technical details to fully follow the discussion, but it looks like support might have been added to Firefox ("Status: RESOLVED FIXED"): https://bugzilla.mozilla.org/show_bug.cgi?id=478839
This commit definitely makes it look like something has happened: https://hg.mozilla.org/releases/mozilla-1.9.1/rev/653b75a8f4...
I believe that's because all online banks don't use SSL/HTTPS, but instead some different encryption standard, which is only available as an ActiveX plugin, i.e. Internet Explorer only.
This is not really a truely free market where people can change.