People don't understand how they benefit from other people's freedom. If they did, then they would have voted this up rather than down.

No. Starting a discussion with the title is political concept X less wrong, indicates that you are ignorant of how this community thinks about rationality and thus get voted down. Not arguing the case for the concept adds further insult to injury.

Even if people would agree with the basic idea, the post likely still would be voted down.

Two directions to approach the question of "why they hold that right so dearly":

1) this direction of funding is a huge part of how they get paid and reelected. It's the major reason that lobbyists and firms are willing to spend money on influencing congress.

2) this direction of funding is intimately tied to the justification for taxes in the first place. If congress doesn't agree with the spending, it wouldn't levy the tax in the first place.

If the government feels it necessary to take money forcibly, it's because the government believes it can spend that money more wisely than the taxpayers. If it believes the tax base should individually choose how to allocate their money, it doesn't need to tax them and poll for how to spend it, it can just take less taxes in the first place and let the populace spend/give directly to important causes.