It only sounds abstract if we just focus on the era of fashion we have experienced, where the designer is hardly a creator and mostly showman with the ability to morph, when needed, into a through and through businessman. It wasn't always like this. They were treated as artists at best, and as excellent, innovative tailors for the most part. If you juxtapose it with other fields with other creative people, like.. I don't know, art, you'll see a foundation remains to promote the legacy of a painter or sculptor, but you definitely won't see a debate of 'ugh, it's so important someone keeps painting and signing as Robert Rauschenberg! his work NEEDS to continue'. In more practical fields similar to fashion, like architecture, you also won't see 'John Johnson for Frank Gehry'.
Maybe the only field where the amount of profit you could still make would be so high and irresistible that the show must go on with or without the artist is music, but even that industry, often so dirty, keeps some principles and refrains.. but imagine how truly shitty that would be, if a bunch of nameless, questionably talented guys that are able to get hired and perform under the name 'The Beatles' 'Stone Roses' 'Pink Floyd' are the ones still selling out arenas, topping the charts, monopolizing media outlets and winning all the awards... it would get so vicious you would not just have to really struggle to find new music, at some point it would feel like there is no choice but to pick among these people pushed down your throat by music labels, and any new band would come off as a 'loser' that hasn't quite yet made it until they're able to finally get hired by The Beatles and play again and again these good ol' hits that your grandparents danced to. It would be insanity.
This oversensitivity some feel towards these old fashion houses like 'but it's legacy!' 'it's a part of our culture!' 'what would we do without it!'.. well exactly, what would someone do without the umbrella of some deceased person's parameters? anything. Plus how insecure and lacking in faith the perception of a city's arts/creativity must be to doubt anything that is new and hold on for dear life to the 5 ateliers that once made something great for a generation that is now largely death.