The important point is the reason why a coin has value is that there are a lot of people mining / investing and trading and a large percentage of these people are the GPU miners. If all of them move to the ASIC resistant coins, the normal scrypt coins will only be propped up in value by the very small number of ASIC miners....Tell me how the small number of ASIC miners will have enough money to keep a coin alive...they can mine 10 billion scrypt coins in a day but if the majority of the community is investing and trading in ASIC resistant coins, then what use is the ASIC???
Look at DarkCoin, VertCoin, MicroCoin and even Ethereum are heading toward ASIC resistance because the goal is to distribute and decentralize....not keep the wealth in the big fat cats who are such a minority.
So called ASIC resistance simply makes it less likely that small ASIC-designers will get around to making ASICs for the "resistant" coin, thus in the long run such coins will probably end up more centralised rather than less centralised as only the largest/richest ASIC companies will have ASIC farms mining them...
-MarkM-
Constantly increasing N-factor means that they would have to make another ASIC every N change, and every time it would get more expensive. I just don't think it'd be worth it.