Music publishers could demand better DRM in their contracts, though. That would lock out any devices incapable of receiving DRM updates, but it's certainly a possibility. If Spotify would refuse to budge, their platform would lose access to a lot of songs. If they agree, their users would have a terrible experience, only being able to play some songs on some devices.
In order for Spotify to have any decent user experience, they need to nip any DRM bypass as scale in the bud before the publishers find out, through cease and desist or worse. If better DRM becomes the only solution, everyone loses.
The difference between official and unofficial clients is that Spotify can have some (contractual) power over the official clients, like demand that music is cached encrypted, demand a certain limit for cached music, etc. Unofficial clients aren't bound by any contract, so the developers could easily do something they shouldn't be doing according to the terms and conditions Spotify lays out (or the terms and conditions of the copyright holders that Spotify must uphold).
In order for Spotify to have any decent user experience, they need to nip any DRM bypass as scale in the bud before the publishers find out, through cease and desist or worse. If better DRM becomes the only solution, everyone loses.
The difference between official and unofficial clients is that Spotify can have some (contractual) power over the official clients, like demand that music is cached encrypted, demand a certain limit for cached music, etc. Unofficial clients aren't bound by any contract, so the developers could easily do something they shouldn't be doing according to the terms and conditions Spotify lays out (or the terms and conditions of the copyright holders that Spotify must uphold).