Bitcoin has dual usage which can be use as a currency and also as an investment, that is why bitcoin is referred to as the digital gold. I believe in the future people will learn what bitcoin really is and will appreciate it for it value but in whichever ways bitcoin will survive the and become a mainstream currency.
Bitcoin is just not for investment and neither it just needs to be used for exchange of goods and services. Though the usage is less that is due to not many countries have completely legalized it. So, people are sceptical to use in their daily life’s and thus majorly being used for investing purpose and nothing wrong form their side too. This is giving them some profits so it’s an additional revenue for them. Also, merchants need to accept the bitcoin against their service and they are not ready due to lack for proper rules.