I believe, but could be wrong, that the differentiating factor is that coke from Mexico is made with sugar.
J. Kenji Lopez-Alt did a study where he concluded that people who think they like Mexican Coke more than Regular Coke simply enjoy tasting Coke out of a glass, and the perceived cane-sugar vs HFCS may just be a placebo:
https://www.seriouseats.com/coke-vs-mexican-coke
But YMMV. Even having read that study, I still prefer Mexican Coke.
Even if a placebo, it's still true - I can't stand canned coke. I can't drink it, the taste to me is horrible.
If all your brain/tongue perceives as horrible is the taste of the aluminum can, you could always switch to buying Coke in glass bottles, which are more expensive than cans but still cheaper to buy in bulk than Mexican Cokes, and can be found at most grocery stores.
Or, if being limited to Mexican Coke means it reduces your overall soda consumption because you're only able to drink it when you're near a Home Depot, keep doing what you're doing. You'll probably be healthier for it.
Or just pour it in a glass?
You're assuming that the taste is only affected by what it's being served in, not how the liquid was transported. For all we know, aluminum imparts some sort of off-flavor into the Coke itself that the OP doesn't like, in which case it wouldn't matter if he decants it into a glass first--it would already have been "tainted" by being held in the aluminum can.
I also can't stand plastic bottled sodas, and can tell they've been sitting in one even if drank out of something else after opening.
I fear the bottling/canning process and length of time spent in it gives it a bit of a whiskey-barrel style finishing taste alteration.
And twice as much caffeine per ml.
Mexican Coke doesn't use cane sugar anymore. But when it did, I'd read that the sucrose in peak-era Mexican Coke broke down into a HFCS-similar mix of fructose and glucose in the drink's acidity anyway.
I'm convinced the Mexican Coke thing is just some hipster thing, and Coca-Cola is glad to exploit it.
I think the real differentiator is drinking out of a glass bottle vs. a can.
There definitely is a subtle difference. I was about to pick out the different drink reliably. It's just hard to imagine the difference is make-or-break between enjoying and intolerable for anyone. And it less likely comes from the sweetener and more from the Mexican water versus the water at your local Coca-Cola bottler.
West coast Coke vs East coast Coke would be an interesting test I've never thought about doing.
In contrast, using 15% ethanol uses 15% less gas at a time when we were desperately trying to not be held by the balls by the middle east gas sellers, it's trivial to produce at scale, it was a simple handout to corn growers, which the US cares deeply about, and refineries didn't mind that it reduced the energy density of fuel by a couple percent, requiring you buy more gas for the same amount of energy, and it would never end up with a 60 minutes special about how it has been poisoning all of us for decades. We should have been using it the whole damn time.