I still don't get while everyone thinks he destroyed the true spirit of the house. Yves was a pioneer in ready to wear and always desired to create clothing people would actually wear; exactly what Hedi is doing. There are multiple well written articles on the topic (I reccomend everyone reading )
Weather his YSL was your taste or not, that's an opinion, but at the end of the day he stayed true to himself while staying true to Yves St Laurent (the man, not the house, which is irrelevant since the day Yves stepped down).
Bigger picture; fashion is the only industry where the artist becomes a brand and lives beyond an artist; could you imagine somebody paining for Picasso when he died, or who would take over for Beyonce when she retires from singing? We have to understand that designers are only human; from Nicholas to Raf to Hedi, the industry relies on them too heavily for financial rewards while not investing and nurturing their creativity. It would be a disaster for any true creative designer to not be allowed to express themselves and grow the brand.
At the end of the day, high fashion now for the majority of brands (speaking mainly of those run by conglomerates such as Kering or LVMH) have a responsibility to shareholders - it's really just a business. It's become almost irrelevant which designer will create a legacy, now that all most can afford from a label is an entry level t-shirt. We can all complain about how the glamour is gone, but really it's been gone for a while. Gone are the days when a brand relied heavily on evening-wear.. I mean, go into most shops - you don't see gowns on the racks. It's just not the way we dress now. I think Hedi's true legacy is that he's the created the one major house that's fully realized the way people dress and how they shop and interact and he gave them everything they wanted.