It all depends on the kind of content you are trying to create. If you are creating vlog type content then it definitely helps to have a large quantity of videos and it mostly just matters that you keep the content interesting through personality and relevant banter on topics of interest. If you are a tech news channel the same is true. Search and suggested views will be where you get the bulk of your viewership and having hella streamlines SEO/Titles/Thumbnails will be your key. Getting 50-100 views per day on 10 videos is a lot easier to do than getting 500-1000 views per day on 1 video.
This, however, this is NOT true of all sorts of content. For instance, I do a ton of production on the videos that go up to my channel BeyondSlowMotion. The same can be said of my good friends over at KumaFilms. It takes lots of time, effort, and money to create the videos that we create. So we do not post anywhere near as often as the aforementioned news & vlog channels. On the flipside, we get WAY more views per video as an average result. I only have 83k subscribers, but in 2014 I averaged 240k views per video only posting once per month as an average. My friends at Kuma Films average over 390k views per video with only just over 100k subscribers to their name.
So again, it really just depends on what kind of content you are trying to create and how you much time, effort, money needs to go into production to make it. Obviously if you can maintain top quality and still get more out it would be highly advantageous, but really you just have to evaluate what your goals are and whether or not your market minds the quality of content you produce. Make sense?