In an economic sense,
 An INVESTMENT is the purchase of goods that are not consumed today but are used in the future to create wealth.
                                        In finance
An INVESTMENT is a monetary asset purchased with the idea that the asset will provide income in the future or will later be sold at a higher price for a profit.

I really don't want to turn these into an economics class but the both definition of what investments are clearly should settle the argument of whether BTC is truly an investment or not.

In my opinion, currently, bitcoin is an investment of economic and financial value. And in the future bitcoin will no longer be an investment but will become a global currency that will be used by all people around the world.

then US dollar is also an investment.

i'll tell you why. where i live the value of local currency is dropping so there are many who are now buying USD to stay ahead of the inflation that is going on. in fact they are investing in USD. and what they are doing matches the description you posted here, they will sell it in the future to get a huge profit.

but it doesn't make USD an investment. US dollar is still a currency no matter what you do with it.
the same thing is true about bitcoin. bitcoin is a currency by nature even if majority are using it as an investment.

maybe according to some people, investment is different, depending on the person's personality
but, the point is Bitcoin is a cryptocurrency that can be used to make payments, through the internet
while blockchain is the technology behind BTC that is believed to be able to change the world in the future

                              In an economic sense,
 An INVESTMENT is the purchase of goods that are not consumed today but are used in the future to create wealth.
                                        In finance
An INVESTMENT is a monetary asset purchased with the idea that the asset will provide income in the future or will later be sold at a higher price for a profit.

I really don't want to turn these into an economics class but the both definition of what investments are clearly should settle the argument of whether BTC is truly an investment or not.

Some peoples may not agree with your opinion, but that is not problem for us because everyone can think what they believe.
Bitcoin has became an investment because the value is very high in the market. In 2010, i think there were no peoples thought bitcoin as an investment.