That's over-simplifying how economics and finances work for a company as big as Sony.
Sony is comprised of different divisions, departments and satellite companies, which also have their own divisions and departments. Regardless of what Sony reports as a whole on their year end fiscal calls, those divisions, departments and satellite companies don't get to spend what they make, they don't get a blank cheque. The money all goes back to Sony.
Sony, like any other large company, will assign budgets to each team, in this case they'll assign $X amount to PlayStation for a years operating costs. If PlayStation meet goals set by Sony and don't spend all of their budget, Sony will reduce their budget for next year. If PlayStation spend all of their budget and meet their goals, Sony will increase their budget. Things like business acquisitions don't come out of this budget, they get handled as special projects which PlayStation would have to present to Sony, with Sony approving or denying and then providing the money if approved.
PlayStation follow suit with budgeting the companies (developers) under them, in the same way Sony do. PD in this case will be allocated money for operating costs and expected to meet certain goals for the year. As PD have recently launched a game that has a lot of issues, I think it's fair to say that a lot of their attention (and so budget) is going towards overtime and damage control, not on expanding licenses for cars.
PD do not get access to the profits Sony reports, PlayStation doesn't either. Everyone gets allocated a budget based on the previous years operating cost, profits and revenue made last year are not a consideration.