[notacoward]

How long before some of those artillery pieces are captured and turned on their erstwhile comrades? The Ukrainians have already been quite successful capturing Russian equipment, and the more they seize the easier it becomes to seize more. Putting more equipment into the theater without adequate personnel and logistical support (which the Russians don't seem to have) won't help at all militarily, and indiscriminate bombardment will only worsen their diplomatic/economic situation. That's why Putin has refrained so far - not some imaginary respect for human life or humanitarian norms that he simply doesn't have.