it only means that we will inevitably need to embrace multiple blockchains. They could be clones of bitcoin or they could be competing cryptocurrencies like litecoin. With a little luck cryptocurrency echanges will be decentralized censorship resistant and ubiquitous in the future. If this is the case than this will make the whole problem a non problem. I dont think this means is that bitcoin will be worth nothing some day, what i do think this means is that bitcoin as we know it has a soft cap on its value. Probably this cap is much higher than 43 dollars or w/e bitcoin is valued at right now.
Multiple blockchains sounds like a mess, considering people are putting their faith into these currencies and a lot of their value comes from scarcity, i'm not sure there is going to be a future with a lot of alt-chains with similar prices. I imagine 1 chain/system will emerge and it will be the one that really solves the block size issue.
Also the only reason Bitcoins are worth $1 - $100 or even more is because many people think that Bitcoin has no transaction cap at all. People think this is the future and the future does not cap out at 7 transactions a second.