I don't understand the aversion to Ethereum (or other alts), especially from speculators that otherwise seem to be pretty dispassionate about the market.

What's wrong with holding a diversified long-term position, where the ratios approximately correspond to your long-term belief of success of the respective asset?

Taking that view, one could still have the most faith in BTC coming out on top, but grant that ETH serves a purpose as well, for example: as a bet on "single competent person in charge of an open-source project", think: Linus Torvalds and Linux kernel development.