Russia isn't going to win the hearts and minds here, that battle is already lost. I'm sure killing civilians isn't what soldiers want to do, so they probably aren't doing it purposely but from Putin's POV being as generally destructive as possible, including on the civilian population, is a way to get Ukrainian leaders to agree to whatever ends the war ASAP. Since it doesn't look like military victory and occupation is that feasible now for Russia, being as brutal as possible is an alternative way to get favorable terms.