If I wasn't sure of the grape, sure I might not confidently say if it's red or white. Because other than visually that isn't really as big a deal as it naïvely seems? Wine doesn't taste 'red' or 'white' it has different flavours and some grapes are red and others are white, but that's really only a visual difference.
(Ok fine some flavours or textures are so much more common in one vs the other that it might allow a solid guess of the colour even if you had no idea of the grape - 'minerally' or 'bready'/'yeasty' tasting/smelling is probably white; very tannic is probably red. But I think my point stands, it's pretty meaningless, and certainty will come from identifying something more specific, and then knowing what colour that is, to satisfy the naïve hater that thinks that's the most important trait.)
And some are blends of both, but we'd call the result white or red according to what dominates. Champagne for example.
I'm not sure what sort of high-quality wine you drink, cause I drink cheap stuff, and I can 100% tell the difference between a pinot noir and pinot grigio.
Red vs. white isn't a coke vs pepsi thing, it's a coke vs mountain dew.
But it’s obviously true that different wines taste different. This is easy (and fun) to test at home.
It's a bad argument that relies on muddling the objective and the subjective. Yes, in a totally blind tasting, people can be surprised by what they think something is. But if I walk into a wine bar, and tell them I like red wines that are dry and have red fruit flavors, they can likely give me something I'll enjoy. If they tell me that there's a white wine that they think I'll like because of that explanation, then sweet, that sounds cool and different. It doesn't mean that hurr durr all wine is the same.
Bro, what? I hardly drink wine, and couldn't tell you whether a red wine is the finest red wine ever or the shittiest, and likewise for white wines, but I can absolutely tell you whether a wine is red or white. Don't know what the hell wines you're drinking.
The lack of tannins, malolactic fermentation, and often the lack of oak will make it pretty obvious they are different. It's like saying you can't taste the difference between a Guiness and a Bud, because you've never had them before? Maybe you don't know which is which with a blindfold on, but you can taste the difference.
My point is mostly about the $3-10 wines which have pretty simple notes. They have very particular styles and relatively restricted grape varietals due to cost, availability, and customer expectations. I'm sure for the right money a good winemaker could take the right white grape and make it taste like a cheap red without the color (lots of skin contact, malolactic fermentation, heavy oak, and some age. On the other spectrum, I'm sure you could screw up and make any wine/grape so terrible you couldn't tell what it came from.
There are also people who couldn't tell the difference between a pilsner and an ale, I suppose.
There are competitions all around the world where you can go and literally watch people doing this in real time. Anybody can learn to fairly reliably identify 5-6 of most common grapes in a blind tasting with a bit of practice.
That doesn't mean I can't distinguish two songs, or that I can't like one song and dislike another.
People may not be able to identify wine tastes very accurately, but that doesn't mean that "anyone telling you they can taste the difference, even between red and white wine, is lying". Obviously there are differences in taste between different wines, and that statement is so utterly bizarre and so obviously untrue it makes me wonder if you have ever tasted more than one bottle of wine.