Deserved it?. It was considered a practical necessity. To let them live could and probably would have resulted in more people rallying to the White cause and thus to the deaths of countless more red soldiers and civilians. On balance better they should die than us.
Bad things happen in a war as the civilian populations of any town shelled or bombed in the Twentieth Century can testify. The only argument that makesd any sense is that of military necessity. Sometimes, like Dresden, its just revenge.
On purely humanitarian grounds of course the Reds should have attempted to achieve their political and social objectives through peaceful and preferably legal means rather than by direct violent action from which only war could result. I rather worry to imagine a world where 'necessity' was the only reason we needed for taking human life away. I don't think its particularly controversial to say I'm not much a fan of the actions or attitudes of the historical Reds or Whites and would much rather mess around with their BoB versions than the realities.
To choose a more interesting and somewhat more relevant point here's something I was previously unaware of: in the 1904 Russo-Japanese war there were high casualties from barbed wire defences- because they were electrified! I wonder why nobody did this in WW1?