If a rotten walking corpse came up to you and started to talk to you, would you really just continue like everything is as it should be? Most likely no. I understand that liches can keep their sanity and act like regular humans, but they wouldn't be accepted by the rest of the population and they would still be treated like evil beast and attacked on sight.
TES does not take place in real life. If an orc came to you in a street what would you do? I'm sure I would run in the oposit direction screeming, the same aplies to Khajiit and Argonians. Yet these are quite playable in TES. If you wish to say that liches would be feared on sight, provide a lore support for this. If the next TES take place in Skyrim, we know that Nords revive their own dead making them some kind of a zombie (they even have a special name for them, but I cannot remember now), so that would suggest that they are pretty much accustomed to dealing with undead.
Secondly, a lich does not have to look like a corps, there is no evidence that becoming a lich will strip you of your flesh and thirdly, even if it does, you can still disguise yourself as I have mentioned several times already.
I'm not against becoming a lich in the game as long as it's done in a proper and realistic way. This includes people keep distance to you or attack you and it should be really hard to become a lich. It shouldn't be something that can be done in a few ingame days, it should take years of hard studing and practice. And that is something that I doubt Bethesda will succed with and therefore my negative disposition towards pc lichdom.
The process of lichification should be something that takes time and is difficult to do, sure. The timescale, however, is a metter of debate. TES is known to have a terrible timescale. You can become a hero of the whole province from a total looser in something like 3 months in TES III and IV. If that is possible, why not becoming a lich as well. Besides, what should really take long is finding a way to make oneself a lich, as a player, you might be given this information, so the research does not bohther you.
I am basing my argument on nothing more than common sense. A person may had been whoever they wanted before becoming a lich, but after that it's over they're dead. What it means is they do not care for the world of the living unless they did what they did to get revenge after transformation. For that matter they probably didn't care for the living any more before becoming a lich, that's why they did it. In lichdom they don't feel anymore what they felt as a human, they shed their mortal shackles, all of them. They might however use logic(depends how crazy they were when alive...) and logically they might and they will encounter "obstacles" which they will simply remove. The process of becoming a lich may not invlve anything evil in itself but it takes a certain kind of person to undergo it and it sure doesn't make them more sensitive afterwards. I can't imagine becoming a lich being a selfless act, exactly because everyone knows the consequences and selfish acts of that magnitude do lead to evil at some point. So does immorality, there's a reason why so many immoral acts are forbidden by laws. Besides someone already wrote in this thread that you wouldn't be able to "enjoy" the full path of lichdom in the game, since one of the main advantages is longevity. So why would a player do it? You can easily get power through other means(and seeking power through any and all means possible isn't the act of even a chaotic character in my opinion, power demoralizes too). I think that would be the perfect opportunity to act evil and don't feel bad about it. Undead are only as bad as the one who controls them, that's why they're not regarded evil by definition in TES. But if the undead control themselves, they become hostile creatures which equals evil in the world of games. We may get into a dispute over the fact that even corpses need to eat and can you blame them for that, but in the end THEY F**IN' KILL PEOPLE and they target them as best nutrition, so they might not be purposedly evil but thir presence sure is. Ok, I might've gone a little bit too far there, but similar rules apply to liches, they don't have real morals, they might remember them, but they're not bound by them anymore. So why would you want to play a creature like that and not make use of the perks? To become a lich and then cry about doing it? While I'm not saying it couldn't have happened in the world of TES(one of the first liches probably was like that), but that's not RPG anymore, that's an emo symulator...an emolator,heh...
Well, but common sense hardly applies here. We are discussing game mechanics. Half of the things in the game are against common sense. That is why this is a fantasy game and not a real life simulator. What remains of you after the ritual of lichification is up to the devs to decide. Remember, that you cannot compare the game liches to their real life counterparts as there are none.
From what we know so far, becoming a lich does not have to be illegal or immoral. And TES lore describes a case of someone who became a lich as a selfless act (or what is more selfless then protecting your village from demons, dspite the fact that your own tribesmen chased you off?), so again, you assumptions are counterd in the lore.
The purpose of becoming a lich is to gain more power, sure, but wanting to have more power does not mean that you are evil. before the election a president candidate wants more power too and not all presidents are evil. Power does not make you evil, the way you use it does. The second reason to become a lich is role playing. There is no greater goal my necromancer can achieve. And that is what the whole game is about, isn't it? About role playing.