A lot of daedric missions are kind of twisted but joining them gives you more gameplay length.

Take for example the dark brotherhood, you can join them and introduce a number of new quests. Or you can destroy them in one quest. Or you can avoid killing Grelod the Kind altogether. Each choice gives you less future options.

The only Aedra mission I can think of is the Mara thing.

There's also the Heart of Dibella.

Plus, there are plenty of quests out there; skipping the Daedric quests will hardly put a dent in the amount of gameplay length. And there are some (Meridia, Azura) that wouldn't be objectionable even to someone roleplaying a "good" character.

There are actually 3 different Aedra missions. Daedric missions have akways been a part of tes. Unfortunately, the devs decided to not include as many Aedra missions as say Morrowind. But its better in Skyrim than it was in Oblivion. That's a good thing I guess. And some Daedric missions have to do with priests of certain Aedra. Like that one in Dawnstar.

Oh, yeah: forgot The Blessings of Nature (Kynareth). There's also Kyne's Sacred Trials, which could be considered another Aedra mission, even though Kyne and Kynareth are the same.

I don't mind that there are so many Daedric quests and not as many Aedric ones... what I mind is being railroaded into Daedric quests and then having no option to refuse them, or being treated for the rest of my game as though I became some Prince's champion when what I actually did was "fail" their quest by doing exactly the opposite of what they wanted.

I don't like how Skyrim forces Daedric quests to the player, most times not giving a decline option... that doesn't sit well role-play-wise with my Daedra-hating character.

Much as I hate having to plan my travels in Markarth to avoid that Vigilant guy checking out the abandoned house (I answered his question; why won't he leave me alone?!), at least I get the option of brushing him off without triggering the quest. Not so with others I could name. Even the Mehrunes Dagon quest stays in your journal, even if you turn the guy down.

It's less a lack 'aedric missions' and more that Bethesda seems to have forgotten that there are legendary items in TES that are not related to Daedra (or aedra, for that matter)

Yes.

I wouldn't say forgotten. I mean just look, we got the Staff of Magnus again, as well as Auriel's Bow. Granted, the bow ain't vanilla, and you don't get the Staff from any temple quest.

I do miss Orgum's Coffer though

skyrim in general is sorta cynical, seems like the majority of quests involve the dragonborn being a [censored] bag