Anna, I don't buy from those brands, for exactly those reasons and more besides. You're absolutely right though, there are far worse offenders than Maison Scotch. That Topshop case is by no means unique.
I appreciate that we're all negotiating complex choices around fashion ethics and how we consume it. I make my own decisions on that front and I'm not going to judge others for making theirs. There are all kinds of rationalisations needed to justify this purchase over that one, but at the end of the day we all need to put clothes on our backs. I will, however, share my knowledge and try to maintain good faith, for whatever that's worth.
So my very Cassandra-like observation here is that there's a world of difference between the positive and necessary cultural exchange that links an artist like Bispo do Rosario to Stephen Sprouse or Keith Haring, or to the embellished menswear at Valentino, and the practice of reproducing heritage artefacts outside their original context and passing them off as fashion. This is the grey area of cultural appropriation that regularly has us mired in so many fruitless discussions about what we should and shouldn't wear, but always seems to bypass the very obvious question of what constitutes healthy cultural creation.
And honestly, I don't have a good answer to this. I feel more or less the same way about Isabel Marant and Ralph Lauren, but I have clothes by both those brands, so I'm not about to call you out for buying this jacket. I'm looking forward to seeing it in fact. I hope it's as nice as it looks in the pictures.