Better solution
The only way one should take the risk from a mathematical point of view is if the potential outcome would outweigh the risk
In a formula:
potential score * probability of success >= original score
10 points * X >= 8 points
the probability of overtaking without suffering damage has to be at least 80%
If we change the scoring from what it was or what it will be (no real difference) to:
1024,512,256,128,64,32,16,8,4,2,1
or in other words one gets twice as many points for overtaking the guy in front of him as he would staying in his place
the probability of overtaking without suffering damage has to be at least 50%
So they could take more risks (we know overtaking in todays races poses almost no health risk) and deliver more fun for the spectators.
One aspect that needs to be taken into consideration is that also the defending driver would take more risks and therefore diminish the probability of the attackers success.
But we don't really care that much about who takes the points (well we do) but we also would like to see more action and that would certainly be the result.
The only purpose for this new 25,20,15... scoring system is a differentiator at the back of the grid.
The 2x more points for each place is not the same as Mosley's medal proposal since in this case 2 silver medals would equal 1 gold.
God I hate Mosley!