Now, I buy whatever I want wherever I want it / is cheaper - I will not pirate literature. I then never download it from the retailer - I immediately go and pirate the thing I've purchased. It's actually just easier. It's easier for me to have a torrent server sync eBook/cbx/pdfs to a folder, that's rear-mounted in google drive and shows up on my device, than it is to deal with what app has what book. Add to this multiple languages and you can see why this becomes a bigger pain.
It could be a niche issue.. But it's also a reason that Kindle/Kobo just aren't big here in Israel, and Android tablets are.