Why should they? They're providing a free service to you and are making essentially no returns on it because you have no viewers. They HAVE to cater to their partner channels because they're the ones that get viewers for twitch, more viewers = more sponsorship and ad money = business
It sucks ass that mobile, non-partner streams are patchy but I dunno if I'd go out to fault them for that. They provide the best service in the world for what they do as-is.
That said... I still think their mobile apps are garbage tier and should be sent to the 9th circle of hell, it's literally as bad as treason and literally worse than Hitler. Hopefully they go through some much-needed upgrades soon, but who knows how soon "soon" really is?