That's just not true, take for example stocks, real estate, etc.
You're correct for real estate.
But wait, stock is the same, some people loss and some people earn, because the larger people invest in stock, it will pump the stock price.
I think that you should accept the fact people use Bitcoin more as an investment than as a currency and centralization trying to adopt Bitcoin. You know, Bitcoin is decentralized, decentralized is where no one can control Bitcoin, so it's up to anyone to use Bitcoin for whatever they like and doesn't limit specific people or institution to buy Bitcoin.
I accept that fact, but that brings the contradiction with it. If bitcoin is an investment and not a currency, than this means the only reason it goes up is because people think that other people will buy it, and thus its price will go up, not because they want to use it as a currency.
About stocks, it's different because when you buy a stock you buy a share of a company, you get some power in the control of it, its profits, not just from the price of the stock.