It's incredibly difficult for a brand to exist on its own profits and without outside financial banking. But this of course compromises the artistic vision of any designer, as a financier is going to demand a return on their investment by whatever means necessary.
Want an example? Martin Margiela left MMM a few years after Diesel purchased the House and caused friction between its secretive designer and the marketing-driven strategy of Diesel. Why purchase a boutique and ground-breaking artistic company if it's not going to make you money by selling its vision to the masses?
Two massive conglomerates alone own most of the luxury brands that dictate the upscale market, and to them it is not about aesthetic or beauty or expression. If designers don't bend to the very expensive market and trend research or hit target profit goals, then they're swapped among one another like skeezoids. Hence the recent shuffling of Raf Simons, Hedi Slimane, and Nicolas Ghesquière. Take a look at the earnings and holdings of LVMH and PPR to peep who really has the final say when it comes to creative output.