If the quest is something like finding a young girl who was snatched away in the night by trolls then NO a quest marker shouldn't be made available to anyone on any difficulty level. If however the quest is go talk with Lorekeeper Alith who is well known and lives in 1 of 200 houses in a big city, then I think a quest marker is very helpful and appropriate. Basically if the location of the quest objective is common knowledge then I would appreciate map markers, otherwise exploration is required, as it should be!