To go back a bit in the discussion (got caught up for a bit and couldn't finish this reply
); I don't mind the DS choices on their own personally:
- Shroom Ridge has been a personal want of mine from back when I thought "Mario Kart NX" would happen; very happy with this one.
- Waluigi Pinball is an unquestionable fan favourite, I know nobody is wondering why this one is included.
- I have a personal preference for Delfino Square, if they had to bring back one DS retro from Wii, but Peach Gardens is fine too.
- Mario Circuit is one of the better circuit tracks in the series (being a Star Cup tier course and all) so I don't mind it seeing it remade for the first time.
I just wish they found a way to slip Airship Fortress in there in addition to the others. Would give DS an equal number of tracks to GBA and GCN. Luigi's Mansion is a relatively simple Mushroom Cup track so I don't mind it missing out too much; especially since we have GCN Luigi's Mansion as a battle course, with an arrangement of the DS track's music.
For 3DS I can't help but admit i'm not a huge fan of the choices, yeah; considering Tour has every track from Mario Kart 7 (the remaining four datamined) available to pick from, Toad Circuit and Rock Rock Mountain don't really stand out too much (except in their visuals, standing out as the worst looking tracks in their waves). Can't say I wouldn't have preferred to see Shy Guy Bazaar (supposedly cut from the base game DLC too), Wario Shipyard (though Piranha Plant Cove lessens the blow on this one a lot), one of the Wuhu tracks (they aren't in Tour yet but they do have some objects datamined), Rosalina's Ice World (not a personal fan but I know others are) or Bowser's Castle (if we aren't getting a 3D Bowser's Castle from another game like N64 or GCN).
It'll admittedly be a bit disappointing to see Tour go down with certain retro tracks that haven't been remade elsewhere before; a Vanilla Lake, Cheep-Cheep Island, Yoshi Desert, Bowser Castle 4, Daisy Circuit, Dry Dry Ruins, (potentially) Moonview Highway and the 3DS tracks listed above; but I think they're striking a good balance between remade before and never remade overall.