Because measuring money is hard and it's not easy to apportion credit.
Person A has an interesting-but-not-exceptional idea and gets Person B to fund it. People C, D, and E code it.
For most interesting-but-not-exceptional ideas you could replace all of these people with others.
If you actually ran this an experiment in a Monte Carlo-but-real kind of a way, you'd find some collaborations would do well, some would do badly, some would fail completely, a few might explode (in a good way).
How do you quantify the value of the relative contributions?
Person A has an interesting-but-not-exceptional idea and gets Person B to fund it. People C, D, and E code it.
For most interesting-but-not-exceptional ideas you could replace all of these people with others.
If you actually ran this an experiment in a Monte Carlo-but-real kind of a way, you'd find some collaborations would do well, some would do badly, some would fail completely, a few might explode (in a good way).
How do you quantify the value of the relative contributions?