You are indeed right about the best method to avoid charges from Lorrick but if tank runs in a circle DPS and healer are not exactly immobile statues they can adjust, too
We are talking about PuGs in first place..
And even in a solid group, some healers can feel themselves more comfortable at the steady places to make their channellings.. so with some ranged classes aswell..
It is more safe to just hide behind Kolto Tank and to not expose the group for Lorick's charges..
Let the Kolto Tank eat all the charges.