The US has in fact sanctioned Russian officials associated with the annexation of Crimea. [1]
You might also spare some sympathy for those residents of Crimea who did not wish to join the Russian Federation, for example, many Crimean Tatars. Not only have they suffered the loss of access to github, they also have to contend with a campaign of political repression. [2]
We should instead sanction people associated with Russia’s totalitarian government.