Yes, I find that I am looking at my character's appearance all the time so naturally I find it is necessary to be able to change it... No I think Bethesda shouldn't waste the time on things like that when they could be using that time to make quests better. Seriously, how often are you looking at your character's appearance in Skyrim? it isn't like Oblivion where you actually got to see what they looked like up close.
Not all the time, but if you're roleplaying a character that spend months in the wild and he looks cleancut than it takea away from the experience. At least if you're a roleplayer, and this is a roleplaying game afterall.
And adding this option wouldn't take time away from developing new quests. The system that changes your character's appearance is already in the game. They can just activate (parts of) it through a mirror or barber NPC.
Besides your argument doesn't hold up, unless you find character appearance compleetly pointless. Because if you're not looking at your character than why have such a feature at all? Afterall in your opinion it just takes away precious time that could be used developing quests. So basically you're saying the whole thing is pointless because you don't look at your character. Well, I and apparantly many others do look at our characters. This feature is already in the game, so what is your problem with it?

so to combat this why not be able the function where in battle your character can gain scars and maybe a new spell/potion that you can craft to cure it?