So, instead of modifying a few pixels in a JPEG or some such, a tileset maker would need to trace their 12x16 or whatever designs, then vectorfy them?
Actually, what I meant was that they are made in vector by hand, as opposed to the solution of using an automatic vectoriser.
Vector lines do remain sharp at any size. Making vectors bigger is never a problem; making them smaller might be (obviously you design them at a small size, that will only enhance their iconic quality); but then again, at the sizes when that becomes a problem you'll need a separate tileset to make any sense at all from it, with vectors or pixels alike. So that's not an argument to claim vectors are worse.
It's an argument for not adding vectors, because that size is easily hit by typical tilesizes. A 16 by 16 vector image of a table will scale about as poorly as a 16 by 16 bitmap of a table.
So again, it depends on the skill of the skill of the artist how a picture will look.
Here, let me show you some tiles I'm making for the HD version of stonesense.
Stonesense starts off at the magnification at the right.(The 32x32 tiles)
On the left it the maximum magnification that this will look right at. (They're 128x128)
As you can see, there's certain tiles which look just as right at the magnification on the right as on the left. (Some don't, but hey, that's why I'm testing them). What I'm trying to say here is that a good artist can spread out detail in such a way that the image will still be recognisable at small sizes.
Also, better scaling, whether via multiple tilesets at different zoom levels, or by vector tilesets seems like a lower priority to better graphics support, that depends on the tileset less. Toady and Baughn should first make more things act like creatures, and not use the tileset.
True, I'm personally more waiting for Baughn's pipedream where he would all you to go beyond the basic tileset for terrain. That would clean up all graphics tilesets so incredibly much.
I'm just refuting the arguments because I think it's unfair on poor vector to get all this bullshit thrown at it's head just because it's not commonly used in tiled-games and can't be made in MS paint. It's a decent image-technology, how good it'll look just mostly lies with the artist.