That is one possible scenario. But it does not mean Bitcoin will die. It will always be there as a store of value. A kind of "digital gold" which is something how, most of the people who are hoarding it, see it anyway.
Agree. Even if Bitcoin doesn't get to scale, it will always be in the eyes of investors and everyday people, to be used as digital gold. Due to its limited supply, and deflationary nature, it may continue to rise in value the scarcer it gets.
Thus, Bitcoin would be used as a reserve currency for other cryptocurrencies, while altcoins take the lead in handling everyday transactions. We've already seen alternatives like like Bitshares and Ripple, which can handle more transaction throughput. It would only be a matter of time before people start using them more than Bitcoin itself for their daily transactions.
However, if Bitcoin comes at a consensus level among the miner's hashrate, then we could see a bright future for it. There are many proposed solutions to make Bitcoin scale, but only one shall prevail. When that time comes in, expect for BTC's value to increase exponentially. Just my opinion.
