A medium of exchange is a tool, and tools people use have value.
I grant the majority of the market is speculation but many of us actually regularly use Bitcoin for things like payroll, settling debts, cheap international value transfer, buying coffee, and for cash-like privacy for online purchases.
For those like me that have been continually buying, saving, and spending bitcoin for a decade, vs simply speculating, dollar cost averaging kicks in. Even 300% price swings do not matter all that much in the long run.
Those that go all-in short term looking to gamble get wrecked, but that is often the case in trading. Bitcoin will be healthier when the short term traders are forced out.