It's not any more of a "fix" than making feats optional. It's simply a difference for those people who don't like alignment, whatever their reason. Alignment isn't racist or broken. If you have the opinion, whatever your reason, that it should not be used, then making it optional at the beginning of the book fixes that. Wanting to ruin it for everyone else is selfish.
It's not that it's a racist tool, but rather such an imprecise one that, when used, can work into racist tropes. Like, there's a difference between something being racist and something that is neutral on its face but ends up enabling racist tropes. Furthermore, it's not even a good tool given that there are so many arguments as to what each alignment means that it hurts more than it helps.
Your analogy would only work if I said removing alignment was like making vanilla ice cream illegal. Obviously I can house rule anything I want.
I mean, no, my analogy works because we're being handed something we don't want and when we want to just stop getting it, people keep saying "Well, you don't
have to hang on to it!" It's like junk mail: sure, I can throw it away, but I'd prefer not to get it anymore in the first place. If you want it, then give your address to DMG Enterprises and I'm sure they can hook you up.
I just think getting rid of alignment as a tool is throwing out a useful tool because some people don't understand how it's meant to be used as explicitly spelled out in the books.
But it's not even a
good tool anymore. Alignment is not a clarifier, it's a
confounder, where people can have distinctly different ideas as to what each alignment means, and thus makes it so no one is on the same page.
Take what
@loverdrive did: those ideas are not only more characterful, but much clearer and more specific that it's easier to understand what the NPC actually stands for. But put in "Lawful Neutral" and there are like a half dozen different interpretations. Chaotic Neutral? That can vary from "I don't like rules" to "I'm literally insane", depending on the edition. For new players, they are going to come in with their own ideas, while older players bring in baggage from different editions that might have varying or completely different interpretations of certain alignments.
Let me give an example: You have a sheriff, and they are termed "Lawful Evil". Now does that mean they are greedy? That they abuse the letter of the law too much? Or are they personally cruel in upholding the law? There's a bunch of ways to interpret because "Lawful" and "Evil": for example, would he be up for a bribe? I've seen plenty of people that argue they should, despite the fact that bribes don't really jive with the "lawful" part.
Now if you say "Always harsh in the law, except when a bribe is in hand", that character's specific brand of evil makes sense: they are cruel with the law, but they are open to bribes. Similarly you could go with "Spare the Rod, Spoil the Criminal", you get a slightly different interpretation, as well as "A coward who hides behind their office and authority". These could all fall under "Lawful Evil", but are much clearer when you rely on actual descriptive language instead of trying to fit it into one of 9 boxes (I suppose technically 11, but whatever).