Problem is that many beta testers are "veteran" of other mmo's where solo quests were indeed solo'able, problem is ESO introduced dodge roll, soft targeting, etc.
All these mechanics that require a lot of visual stimulus training to understand, but since these "veteran"'s come from games where there is targeting or the character skill simply overpower said mob, they think it's non solo'able since they can't kill it by spamming mouse attacks. Sad that they go with them to balance the game, was hoping they would keep it at least a tad hard to make players push their heads.
Many will complain that it's hard, but deep down they're fed up with how easy other mmo's got and would love a challenge, even if initial response is "why no me get zuper lootz frum bozz".