Unreleased OST's

[TheFantomConvoy]

This is especially rather painful if the OST's in question are really good, and I wonder why there are still so many unreleased ones even past the year 2000. It's a thing in both Japan and the West, especially bad in the West though because BGM's for material like cartoons aren't valued much at all.
However, why don't anime studios bundle it in one of their expensive blu-ray sets for anime series that have those, or at least put it up for download on one of their sites? There's almost no excuse not to release an OST at this point in time as long as people will be there to buy it if they like it.