In light of significantly declining sales, iTunes is addressing a problem that seems to have plagued users for quite a while now. According to a report from Digital Music News, iTunes will no longer be accepting cover songs with the original artist's name in either the song title or band name categories. For example, “Roar” (Originally performed by Katy Perry), or an artist name such as the Blink-182 Tribute Band, would not be acceptable. Additionally, songs cannot sound too similar to the original, or they will not be permitted into the store either.
Exceptions will be made under certain guidelines, however, for karaoke tracks, even though most of them have already been hidden from general artist searches, unless you explicitly use “karaoke” as a search term.
As aforementioned, this comes in light of significantly declining sales in download purchasing. In a sense, as Digital Music News stated, it is Apple's attempt to “clean up” the iTunes store.
In the age of streaming, downloading has simply become an inconvenience.