So it's a binary choice between "terrible x" or a "terrible y" system, solely because YOU SAY SO, with no other options other than that?
Everything that you have said that you THINK is a point is tautological.
Not even remotely true of alignment in any edition that I am most familiar with (3.x, 4e, and 5e).
Take 3e, for example, since that had the most in-depth alignment mechanics of any. If you commit one of these "evil regardless of context" acts in order to do something good, then you have done both. Example, you raise some zombies and skeletons from a nearby graveyard to have soldiers to stop an orc tribe from attacking, thus saving an entire town. By the actual RAW of D&D alignment (not to be confused with the grotesque parody that YOU CLAIM is the RAW), you have committed a morally evil act (created undead), followed by a morally good act (saved hundreds of people's lives. Now, according to the rules on how alignment changes (3.5e DMG, page 134), "Indecisiveness Indicates Neutrality". Someone who wants to accomplish Good ends, but is willing to use Evil means to do so is not truly "Good". And the same thing applies to your "doing nothing is morally safe" line of garbage. Such a person would also be Neutral.
Once again, you intend ONLY to discuss alignment in terms of your grotesquely distorted perception of it, claiming that is "true", then you are objectively WRONG, and I will call you on it.
hamishspence answered this beautifully. but you didn't respond, probably because you didn't like the fact that he completely shut down this claim of yours in a way that left you no room to continue saying "but alignment is bad because I want it to be bad". You, in fact, CONTINUE to harp on this point later...we'll come back to it.
In an edition with more concrete alignment mechanics, such as 3.5e, alignment determines how some spells, items, and abilities will affect you. Thus, an accurate telling of one's alignment is significant. If I started out with a party of all Good-aligned characters, but the part Fighter has been doing so much morally questionable stuff consistently over a long enough period of time that he has become Neutral, then when my party cleric casts Holy Word, the Fighter is going to be somewhat affected, while the rest of us are not.
And "Chaotic Neutral as evil or evil lite" is, once again, a fault of PEOPLE. Not every person mis-using alignment is a DM. Sometimes Players are jerkbags, too. That's not what CN is supposed t be, and I have seen (and played as) several Chaotic Neutral characters who are not even remotely disruptive to a party of Good and Neutral characters.
As I said before, alignment mechanics give mechanical voice-in an objective manner not determined by DM fiat-to several classic tropes of fantasy. Also, for what I said to 2D8HP, above.
Moral ambiguity is always still possible, because mortals do not perceive the objective nature of alignment without the use of magic. A PC or an NPC may be as morally ambiguous in play as you like. The existence of absolute objective moral and ethical standards in D&D are on a cosmic scale. So no matter how morally ambiguous a character is, they still end up falling somewhere within a defined alignment.
Of course, if you don't find alignment to be productive, don't use it. I've never advocated that everyone "should use" or even "should like" alignment. If people don't want to use it, they shouldn't. The ONLY wrong way to play D&D is a way in which people at your table are not having fun. I just argue about what alignment is and is not-factually-according to the RAW.
And...we're back to this.
Hamishspence pointed out to you that by a D&D metric, that isn't actually the case. But you wanted to keep saying this about alignment, so you ignored him. D&D alignment actually DOESN'T promote this mantra. And it's a blatant lie to say that it does.