Actually, thinking about it more, it wasn't even so much the stories or the acting or such that made the show fall mostly flat. It was simply the overall background atmosphere. Voyager was just too clean
The uniforms were rank and file neat. Bulkheads and floors were sparkling whole and unscratched (not to mention the most completely bland color scheme possible). Repairs happened at the snap of a finger (or at least by Janeway's second snap). You never heard complaints about food shortages or berthing crunches, replicator failings, or power conservation blackouts. Nobody missed home for more than five seconds, and everyone got along peachy keen after five minutes.
For a ship lost 70 years from home, life was just too easy.