Life is imperfect and changing products require a little research. You can't just go to the store and buy the best socks either; if you want the best you got to do research. Thems the breaks.
The person you replied to was trying to make the argument that a vendor can sell more product if they make the hierarchy of quality more clear to the consumer. Saying 'things are imperfect, as a consumer you just have to deal with it' doesn't really address his argument.
Look at the luxury car sector. https://www.audiusa.com/models#sedans/ Can you tell the quality by its naming convention? I can't. I can sort of assume some quality hierarchy by the price though.
The fact that Apple has abandoned the "one phone, one tablet" model indicates to me that it hasn't been a valuable strategy for them.
Other luxury consumer goods use pretty similar schemes, e.g. Audio gear (e.g. bang + olufsen: the higher the number the better, with some number of meaningless zeroes added depending on fashion).
One observation might be that these companies all have halo products that are used to anchor/promote the volume offerings that drive revenue (e.g. The Audi r8 and the a3, the 90k speakers and the 1k set)
You need to already know the brand to know this.
> (quality: 1-cheap, 8-luxury)
How high does it go? If they decide to turn it up to 11 tomorrow, is 8 still "luxury"?
I can't agree that this sort of versioning is any more transparent.
> (e.g. The Audi r8 and the a3, the 90k speakers and the 1k set)
This means nothing unless you already know the brand. There's going to be a minimum set of knowledge required to understand these versioning schemes.
Growing up in Europe seems to be enough wrt to Audi.
I'm not interested in cars but I have still picked this up somehow. Same with BMW.
On the other hand, I think most Android users I know have told me a story about buying the "wrong" Android phone.
https://en.wikipedia.org/wiki/Confusopoly
heck, mobile phones are the canonical example.
iPad 2
The new iPad (with Retina display)
The new iPad (with Retina display) (again)
iPad Air
iPad Air 2
iPad Pro
iPad (announced today)
The step from Nexus 6 tot Pixel isn't that difficult to understand (and you even forgot the Nexus 6P, the successor of the Nexus 6!). Car manufactures launch new models all the time, without much problems. If someone gets confused by such thing, maybe that person is better of with a feature phone.
Naming schemes are terrible.