Well then those people can take their money and donate it directly to the causes they care about. They do not need to use my tax money for it.
Yes actually some of this money WAS mine. I paid into this system (actually I was forced to under threat of violence), and I do not want my money being spent on this. I would rather keep my own money or have it used on paying down the national debt.
All money spent by the government is ultimately taxation, if it doesn’t come directly from taxpayers it comes from us in the form of inflation. i.e. printing more money than there is value in the economy.