I will repeat the question: by what logic can you "squeeze around" terrain but not "squeeze around" an enemy unit?
Because when you break formation to step around a tree, it won't reach out and brain you.

Oh, and please stop citing final rushes as a precedent for this crap. I will now waste several minutes transcribing the beginning of the Final Rush section of the rulebook:
Then please don't throw a temper tantrum every time someone
dares disagree with The Almighty Kevin, Mmmkay?

The text makes it perfectly clear that final rushes are fundamentally different from all other movement.
The text is a piece of fluff. Its use in justifying or negating precedent has about the same purpose as my son's baby wipes.
Seriously Corey, I have the email you wrote 2 days ago saying you don't care one way or the other about this rule. If you just enjoy getting me riled up, please find a way to do so that doesn't threaten to break the game (or, at minimum, add a big, hairy, oozing, red zit of logical inconsistency to its otherwise attractive face).
Well, I'm not trying to rile you up. But I know that with the ranged fire tweaks, it'll take all of about 67.39 minutes after you play a game where a crucial unit gets shot up for an extra turn because its corner clips some forest before you post up some histrionic screed about how the ranged fire tweaks are "a a bad idea and need to be forgotten."
(Now I'm trying to rile you up.)

I'll be honest I'm not that fired up about this. It's in the same category as the "Endgame CA surplus." It's something that should be tweaked but not a huge deal. I suggested it during the pila debate as a general commentary on terrain and ranged fire. I also think its worth testing out.
We can have a discussion about the need for it and the effectiveness for it, but your argument that because a unit can break formation in a charge but not on the march
to step around the same terrain is just laughable. Given that most units are relatively loosely organized (probably closer to the "heroic" style of 3-5 feet between each man instead of the "Hellenic" 12-18 inches), it's perfectly consistent that they could advance around relatively small pieces of terrain without the entire unit loosing cohesion. In fact, maintaining cohesion on a charge was traditionally harder than stepping around smallish obstacles.
So yes, there is a parallel between being able to final rush around something and being able to march around it.