Because Russia as a whole has collectively worked to destabilize most of the world for the past few decades, and Ukraine was the peak of that plan. Russian citizens let Putin amass this much power, their indifference is causing a global famine, strains of resources, and most importantly Ukrainian civilians are being murdered/putb into filtration camps everyday.

Meanwhile Russian citizens literally don't suffer any consequences at all and gleefully join up with Putin's army to keep fighting and dying in Ukraine. They do nothing to stop the madness in their own country and then run around everywhere else knowing full well that Putin will later use it as justification to invade these other countries like Georgia further in the future.

The only thing that actually weakens Putin is native Russians undermining him and making a stand. Letting these people run off to put other countries in jeopardy will just cause greater issues. They need to fix their country.