where did you come up with this? Where I'm from retailers sell at least 15 models of RX 460 (sapphire, powercolor, xfx, asus, msi, gigabyte, each with 2, even 3 models, and 17 models of RX 470, ranging from blower type cooler, single fan top cooler (RedDragon V2) and the usual slew of dual fan models, some with 4 and some with 8GB of ram, and a whopping 25 models of the RX 480 with different cooler types, 8 or 4gb of ram and varying degrees of OC.
Also RX 470 cards are outselling the 3GB 1060 by 2:1 here. The RX 480 isn't doing as good - sales barely equal the 6gb GTX 1060. If AMD would drop prices a little bit the 480 would sell better.
The 460 doesn't sell very well here. People favor the cheaper GTX 750 or the faster GTX 1050 (non-ti). The 460 should have been either faster, or cheaper.
The 470 is much, much better. I bought a PowerColor RedDragon V2 4GB 470 for my guest gaming PC, and not only is it quiet (despite the questionable cooling solution), it's also very cool and easily matches the GTX 970 in most games (surpassing it in DX12 / vulkan).
I do agree that the 460 is a joke, but I have the same opinion of the GTX 750, the 960 and the 1050ti. The 750 is too slow for my taste, and it never dipped under 150 euro until this summer (in my area at least). The 960 is way too slow for what it costs. It's direct competitor, the 380x being faster (a lot faster in some games) while costing the same. As for the 1050ti - would you believe there's models that cost almost the same as a 3gb 1060 / 4gb rx 470 in my country? And those are much faster cards - up to 50% faster! In fact there's an Asus model selling for 215 euro, while the much faster afformentioned Powercolor RedDragon V2 sells for 208 euro in the same store... (I got it on sale for Christmas for 184 euro)