Getting involved too deep with an international company like Audi (group) puts you at the mercy of a board (or assorted boards) most of which have no idea of or interest in racing and could easily become a minefield of 'we are not making enough, sell it off', and could end up in the position of Williams in just a year or so.
I prefer to see Mclaren as a strong self owned company, but with a good engine supply.
With the cost cap and rules on what engine makers must supply to the customers, I think it is for the best as it is.
Things are coming together, nothing is ever a straight line graph.