Same reason that you shoot at enemy conscripts in a war, drop bombs on enemy cities. Same reason why Russia is now being subjected to sanctions. To undermine the Russian economy in a non-violent manner.

Whether or not it results in political change is irrelevant - a crippled Russia is a sufficient end all in itself, just like dead soldiers are a sufficient end all in itself during a war. Wars rarely end with a government being overthrown, but they do often end when a government decides that peace is the better option. Bombed cities, dead soldiers, and starving children are the calculus that pushes governments towards making that decision.