My point is that if a coin is profitable to mine with gen1 ASIC then gen2 ASIC can merge mine it for no additional cost thus making it unprofitable for gen1. Not like Litecoin that can't be mined with SHA256 ASIC.
Maybe I'm misunderstanding your post.
I don't think I explained myself thoroughly in the OP.
When gen1 ASICs become unprofitable, people will be looking for a way to make them profitable again. There will be a huge incentive for someone that wants to create a truly innovative SHA-256 coin. I will lay out the basic business plan here:
1. Buy unprofitable ASICs for pennies on the dollar.
2. Design and develop a ground breaking SHA-256 coin. Better than all ALTs existing and better than Bitcoin itself.
3. Hash power will be split between Bitcoin and this new better alternative by speculators and people that believe in this new coin being better than Bitcoin. The split in hash power will allow the overlay to make gen1 ASICs profitable because hashing power is split in between Bitcoin and this new alternative coin.
For instance, assuming a 66% monthly increase in difficulty, an Avalon will be unprofitable on May 14th when the network difficulty is 4863 million. If half the hash power switches to a new innovative SHA-256 coin, that would effectively bring Bitcoin difficulty down 50% to 2431.5 Million and you're back to making money again. Plus, maybe this new ALT coins is so much better than Bitcoin, that it is more valuable to mine than Bitcoin itself to due to high exchange prices from speculators. So, it could be a greater than 50% reduction in hash power in that case.
I have been right about a few things since I came on these forums and started posting. 1. Litecoin, 2. BFL being shady, I hope these won't be the last either. It is somewhat of a wild prediction, but I like throwing as many conspiracy theories out there and seeing which ones stick. Then I can bump this thread in a year and bump my chest if I'm right.
jk (or... not).
Also, it doesn't even have to be a new SHA256 ALT coin. Perhaps a lot of development is done to an existing one to where it is more valuable to the community. Huge market shifts (UP!) in the value of SHA256 ALT coins could dramatically change the profitability of SHA256 mining.