There is the other matter of counterfeit goods, if you make a T shirt and put three stripes on it and stitch 'Adidas' on there then that is a counterfeit. In the examples above where Zara have stolen someone's hard work, this is definitely copying, not counterfeiting.
So long as nobody is counterfeiting stuff then all is good. I also think a lot of artists would be delighted if Zara stole their ideas, at least they get some validation which is better than being ignored.
Few do it for its own sake in anonymity (though there have been a few).
As an aside, there are many amateur photographers who don't care about the money because for them it's a hobby and put stuff up as CC and some professional photographers hate that because agencies will use a CC instead of paying for a commissioned work (depending on use and license).
So, basically, it's akin to when you liked a music artist but didn't want them to become famous so you could keep the artist to your cool circle of friends but of course the artists wanted to become better known so they could actually make some money to cover the bills and then you got to call them sell-out and poseurs.
There are degrees of success in any form of commercial art, and the people companies like to rip off are not people pittering away in obscurity or hobbyists. Instead, it's those that are appealing enough to get by and have an audience, but with not enough resources to mount a significant legal defense to their out-and-out thievery. If you look into the Zara case, these are the exact circumstances of the illustrators from whom they're stealing work.
I understand that audience members have different kinds of social relationships with works of art, but you should trust artists when we say we don't want or need wealthy conglomerates stealing our work. In the age of the internet, we have tools to get our work out there (thanks to those on this site that work on building these tools). And if large companies want to find and pay to work with us, well, that's even easier than ever too.
Anthony Clark got ripped off by Little Caesar's just yesterday and is a long way away from 'delighted': https://twitter.com/nedroid?lang=en
[0] http://shoparttheft.com/ [1] http://www.cbc.ca/news/trending/zara-stealing-artist-1.36890...