Without coming down on either side, the simple answer here is because the funding company would be ahead of competitors.
In high-tech markets, pioneers often develop durable leads (Apple, Microsoft, Oracle, Amazon, etc.). There's a huge business advantage to having the IP + the team that developed that IP in one place.
Conversely, handing over IP alone doesn't build a business. For example, Tesla could give away all their private IP for the Model 3 and it would still take a lot of investment for a competitor to arrive at a parity offering (which would be years behind, because Tesla's teams haven't stopped). Because the product is much more than a sum of the basic research.
If I offered you an deal that paid you $10 for every $1 invested, with the caveat that it would also pay your competitor $11, would you actually not accept it?
Wouldn't it be rational to wait for my competitor to take you up on that deal? Then I could spend the extra money on research that only benefits myself.
Surely more rational: club together and pay the cost you all pay less, you can repeat and get access to even more opportunities, you can all get the benefits.
Applied across all actors, your strategy results in nobody taking the deal, the worst outcome for everyone but me.
It’s such a strange, “everyone loses” attitude, but people are strange. Studies of the Ultimatum Game [1] show that people will actually refuse free money if it meant someone else got more.
