Criticizing Bitcoin investment for speculation rings hollow when the majority of equity investment is speculation. Very few people invest with the intention of never selling. The news has a daily ritual of reporting the rising and falling of stock prices.
Well, when you buy shares, you buy a stake in the company, i.e. a share in the company's assets, which per se represent a value (and of course can be completely overvalued). When you buy precious metals, they also have an intrinsic value. What countervalue do you have when you buy Bitcoins?
Whether an asset has cash flow is besides my point. If one buys an asset with the intention of selling later at a profit, they are speculating. It’s fine to criticize speculators, but my point is it is not exclusive to Bitcoin. The majority of all stock investing is speculation. Very few investors buy stock purely for dividends with no care for whether the price will rise or fall. If Bitcoin is a “ponzi” because buyers are hoping to profit from rising price, then the stock market is also a “ponzi.”