The tracks aren't the issue (although Sochi is a dreary hole which should be removed ASAP), it's purely the cars not being able to follow each other. Quite why the FIA still hasn't addressed this by bringing back ground effect is anyones guess.
BTCC proves you don't need world class tracks to have great racing.
I thought I heard in the commentary that DRS is under review as to whether they will keep it, surely that will make the problem even worse