>This analogy does not hold because nearly any musician will jump to the opportunity of sharing their gear and setup.They'll share info on music gear forums[1] but not on Soundcloud. One could visit 10 rappers' soundcloud page and leave a comment asking "what microphone did you use for your rap vocals?" and you usually won't get a reply. That's normal. A lot of musicians upload their music but don't engage with the comments left by users. Musicians aren't being secretive on Soundcloud; they simply don't view it as a Q&A platform.
In any case, what I meant by "items not easy to source" for Soundcloud analogy is that there is no "add to cart" or url for the products you hear in the song. E.g., there is no button that says "Buy the Shure SM58 vocal mic you're hearing". In contrast, Pinterest has direct and obvious hotlinks to retailers' websites.
Therefore, getting frustrated that SoundCloud "doesn't make it easy to source the music gear you're listening to" is to misunderstand what SoundCloud is about.
[1] gearpage, harmonycentral, gearslutz, etc: https://www.google.com/search?q=music+gear+forum