If the rebuttal is "yeah but advancements improve the economy" -- The private sector can fund projects which are opportunities with an economic basis, they can take the risk and they can see if it is profitable in the market (ie beneficial)
If the rebuttal is "How will America stay competitive?" We cant seem to keep trade secrets anyways. [1]
[1] - https://www.bbc.com/news/world-asia-china-64206950
Edit: Also the 4 years at a time thing is probably a better choice too, because it makes them less twitchy politically. You get your 4 years, regardless of who's team is in office. This should be a win regardless of your affiliation.
The private sector can only fund easy low hanging fruit productization projects (Tesla, Apple, SpaceX, …) once the hard public fundamental research and infrastructure (Internet, Rocket Science, Physics, etc…) that has no short term economic value investment is done.