You are mistaken in your comparison. the subscription on patreon is a deal made directly between provider and consumer. Steem is not that, as a vote comes out of a shared pool of resources.
If it makes it easier to understand, see the Steem pool as a shared wallet between a group of people where any purchase made has an opportunity cost and affects all others in the group and their ability to purchase. If there is a 100 dollars in the wallet and someone wants to buy something for themselves with it, all others will have to go without. The downvote is a challenge of the purchase or perhaps, "the right to return" what was bought for some money back.
Not "directly", there's a corporate middleman that has veto-power over the deal.
Also, it's purely voluntary, just like an upvote.
This is exactly like cash-money-dollars.
If fewer people SPEND cash-money-dollars, then the cash-money-dollars that DO get spent are worth MORE (deflation, reduced liquidity).
If MORE people spend cash-money-dollars, then the cash-money-dollars that get spent are worth LESS (inflation, increased liquidity).
If you could stop people (through some mechanism, like downvoting) from purchasing dumb stuff, or stop them from tipping drivers and servers and hair-stylists, THEN your money would be worth slightly MORE than it currently is worth.