It's less to do with me personally wanking off capitalism, but it's really the best system that has been tried. In fact it's not really a system because it's not been designed, it's the organic result of free trade of goods and services for mutual benefit.
It's also the only economic school of thought that fits into my wider world view: people should be free to live their lives as best as they see fit, and to never be an aggressor (Non-Aggression Policy, or "NAP" in libertarian parlance).
Taxation is simply incompatible with that (although voluntary taxation such as VAT are begrudgingly acceptable). It's not selfish, it's not greedy to think like this: it id straight up theft.
I don't normally like using analogies and equivalences to illustrate points but they're quite useful in this context, because people are brainwashed when it comes to taxation.
If a man approaches me in the street and demands my wallet and threatens to kidnap me and lock me in a cage if I don't, it's theft.
If two men do it, it's theft.
If ten men do it it's theft.
If a hundred do it and decide to hold a vote on whether or not to do it, it's theft.
If a thousand do it, hold the vote, and decide to use the money to give to a homeless man down the street, it's theft.
If a million do it to me and fifty others, with the vote, and decide to split their swag between twenty different causes and even spend it on stuff I use, it's still theft.
If seventy million do all of the above and a fraction of them call themselves "the government", it magically stops becoming theft and becomes taxation and it's suddenly a good thing? It's nonsense.