Its not a myth. The Neo Nazis have been routinely shelling the Donbass for 8 years. The people are sick of it.
Documentation, please. First, the Ukrainian artillery used at the time had a limited range. They could not strike beyond this if they had wanted. Second, they also had limited ammunition supplies. What benefit would the Ukrainians have gained in diverting their artillery from shelling Russian militia positions to shelling a civilian population that they wanted to reintegrate into Ukraine? Third, as I said above, even the casualty reports from the so-called Donbas republics do not support the claim of massive civilian casualties. Just repeating these claims does not make them true.