I don't think anyone can really answer this. I don't think Bitcoin will tank in such a fashion though. I also think these companies that are sinking so much into mining hardware are not doing it just to mine bitcoin. They have bigger plans. When I read about the $5 Million Dollar investment from CoinSeed, all I could think of is a company like Coca Cola or some other large company coming out with their own coin to replace all the stupid ass reward systems that they currently have in place. They'll need someone to process the transactions. If you think about all of the dumb point systems there are and imagine them getting replaced by bitcoin related technologies, you can see how any hardware investment into Bitcoin may have a lasting presence beyond Bitcoin itself.