The longer a movie's been out, the more likely it is that you've already seen it. The global production rate of quality movies is much less than 3 per week. Once you've exhausted* the catalogue then you're either stuck waiting for new releases or you resign to watching movies you're not that interested in. It's laudable that Netflix is trying to hip people to obscure movies that they'll hopefully like (and make money at it, because obscure movies are cheap) but more often than not the movie just sucks. There's a lot of crap out there. Wasting 2 hours on a shit movie burns bad enough that I don't gamble my time on it anymore.

(* I know this sounds ridiculous but some people just don't enjoy movies made before they were born. Most movies are not timeless, and the timeless ones you're likely to have already seen.)