It is normal for investors to hold a percentage of higher risk assets, and to hold financial instruments for purposes other than long term growth, such as hedging contracts to protect against currency fluctuations.
In BTC's case, holding it offers certain characteristics that are hard to get in other asset classes. To someone managing a fund or portfolio, these characteristics have little to do with the technology itself, and everything to how the bitcoin price responds to international events.
In recent years, the bitcoin price has risen when uncertainty around the global economic system is high, or a country (read China) is trying to restrict money flow across its borders. Given recent worries about the US president-elect starting a trade war, bitcoin outperformance at the same time as a strong US dollar (hence a low gold price) is a foreseeable outcome.
None of this is to say bitcoin has any inherent value. However, the fact that its price has reacted to world events in predictable ways has meant that it has been a useful financial instrument.