I got the idea from the link in the op that these coins were already established and remain largely untouched as up until this new script was created, only cpus could take advantage of it?
Dozens of scrypt based coins are worthless, most of the market is based on speculation, you can't easily speculate on a low value, low mined coin so it will likely not gain traction. Considering the choice now between buying a 780gtx and getting a small amount of boost from a coin that is worth nothing, and getting a huge boost by buying a AMD gpu so you can mine a coin that is already worth something, where will the buyers go? It's a simple choice.
Look at the numbers they said, 12 cpu cores 430, a gpu 900 for that particular coin.
A current hexcore intel chip will get 50kh/s or so, while a 290x can get 950+ kh/s, an almost 20x speed up for a coin that has value that will pay off the hardware you buy.
Spending an even higher price, for a magnitude less in speed up 2x vs 20x, for a single coin that has no current value, that can't make certain of hardware payback let alone profit? Who is going to spend enough to make enough huge farms to pump enough value into the coin that it may possible become popular... the answer is no one.
Coins are gaining real value when they get HUGE support from the community, the ones that get little to no support and little to no mining to no where at all.