I think generally speaking, young people like to be "where the action is." If one has traveled outside of Vancouver to Toronto, Montreal, or even outside North America, ( I know Metro-one you've said this many times before) to cities the likes of Tokyo, Hong Kong, even Shenzen, they all seem to have a vibe going on that Vancouver is missing. Yes the populations of some of those cities are well over Vancouver's, however Vancouver has the third highest population density in North America in the downtown core. I think the people are ready for a light or two.
Is the city suggesting Younge street is ugly?
This is a street scape where people want to come. As you mentioned before Metro-one, it's not as if the entire city must be lit up, but I believe instensifying Granville and Robson, which at this point is not home to any residential buildings with NIMBY's inside to complain, would add some real life to that area. Jlousa you mentioned before that Times Square was a busy destination first and all the screens and what not came after. Could Granville/Robson not be the same? It must be one of the busiest intersections downtown, (at least for pedestrian traffic) and there are tons of people milling about down there all the time. Shibuya is another great example of this but on obviously a much larger scale.
Is Vancouver not ready for any of this? Festivals, we definitely need more of without a doubt. They bring people together for fun and entertainment. As for Lights and LCD screens, gimmicks they may be but they do attract people, are fun to watch and help add a daily vibrancy to an area, (like our entertainment district) that should have it. Granville/Robson should be our little Shibuya, or Dundas sqaure, or what have you. Am I way off base on this?
Also, I love "..areas like Granville, Gastown, Robson, #3 road, Metrotown and even Lougheed town centre i think should be pumped to the max!"

"PUMPED TO THE MAX!!!" Your passion cracks me up Metro-one
Photo credits:
Younge street taken by Matthew Johnson
Shibuya taken by anshirey