Capitalism is a few centuries old. Statistically speaking it's most likely not the economic system we end up with forever. Optimizing for innovation under that constraint only seems premature. To channel Le Guin:
"We live in capitalism, its power seems inescapable – but then, so did the divine right of kings. Any human power can be resisted and changed by human beings. Resistance and change often begin in art. Very often in our art, the art of words."
Taxation is, of course, theft, and any of it's use unethical — but I don't think this has anything to do with my question, which you haven't really answered. I wasn't asking about subsidising or donating either, my question was specifically about investment: act that assumes you expect the returns.
Would you be willing to invest your own savings into tech-centric startups if they wouldn't be able to legally defend the tech they invented?