What if alignments were a continuum and not mutually exclusive?

[KorvinStarmast]

What if alignments were a continuum ...

Originally, they were. The mutually exclusive problem comes with dark light being, roughly, an oxymoron, as is a good evil. See also law versus chaos (or order versus entropy). It wasn't nine boxes, it was a circle or a plane around two axes.
You could fall anywhere on the circle, although Paladins were way up in the upper left hand corner.
(See illustration II, page 4, Strategic Review Feb 1976. (The last one before Dragon got published)).

Wouldn't it be easier to just have personality traits, bonds, flaws and ideals?
You could have alignment derived from that, and from the character's actions, which may be all over the place as far as alignment is concerned. Whether you call it good+evil or neutral is immaterial IMO

You have RP motivations derived from that. It's a great little tool, but it is a complement to alignment, not a replacement for it.

errr.... why would you expect anyone to read 1st edition ad&d rules? why would you consider that as a prerequisite for talking about alignments?

Because it is where the two axis system originated. If you want to understand something, know where it came from.

Wrong. Just because they were published somewhere in the 1st edition, it does not make them part of the rules.

For the same reason I'd expect people to read Moorcock, Poulson or Tolkien, or play original Super Mario Bros., or read a history book: because they are interesting and answer questions of why some things are the way they are today.

Old editions of D&D will stop being relevant once new editions stop recycling their trash.

This too.

"I didn't like one instruction manual, therefore, I have no intention of reading a different instruction manual to see if it explains something better. Like, I don't even use the instructions I did read."

That's equivalent to what you said. Do you see where you went wrong?

I usually read the whole procedure from the car repair manual before I try the repair.

If you don't care about the rules, to the point that you've clearly ignored what the rules actually say, what makes you think you can improve on them?

There are a lot of folks who want to homebrew D&D 5e when they really don't understand the system very well.
As but one example:
We are almost done play testing a dragon rider PC class. It has been in the party for about a year. That homebrew class had been through 8 revisions before we got our hands on it, and then two of us, DM and me, tweaked it a bit more to get the more egregiouly OP bits out of it. It is still very strong after our trimming and I am not sure I'd allow it at my table as a DM ... but it's provided a little bit of fun, to include two of the PCs flying around drunk over the capital city on the back of a flying drake.