You assume everyone wants as many people to hear their music as possible, under all circumstances and environments. A lot of artists want some control over how their art is consumed (as an example, I would like for people to hear my music first over a high-quality sound system, not some shitty car stereo or beats crap), which a users-first 'UX' mentality attempts to commodify.
(And before someone points out what appears to be a contradiction with my previous statements, while I think SC is for its users, its original design was much more artist-centric and extended lots of control to the people who create its content)
It sucks that the artist you reached out to decided to be lame, but my experience doing that has been the opposite.
SC still offers a download option, and as long as your track isn't flagged for copyright you can set it and unset it freely, so the lack of ability to download from Soundcloud has more to do with the artists you are browsing and/or Soundcloud's UI.
By the way, I am fully in support of piracy, so no objections here. As a principle it stands for the ownership of bits and against the commodification of art. Piracy encourages individual pursuit, curation, effort, and even creativity. Youtube and its consumption culture value none of these things.