In short, the issue of corruption in Russia is typically raised by the people (Browder, etc.) who used to like corruption in that country when it benefited them. Which strongly suggests that they actually care about their lost revenue.
It's detailed in a recent article by Mark Ames -- an American who has actually lived in 1990s in Russia (and ran a local English-language newspaper) and who sheds some light on Browder's past attitudes regarding corruption in Russia.
All the good people on the Web who have suddenly started to worry about Russia, take some interest in learning about 1990s in that country. It's the best part of the story which provides the context for understanding the current affairs.