Sunday night wouldn't work for many in my troop. Also, our CO wouldn't approve. Sunday night is when they have their high school youth group. My sons, for instance, couldn't do both.
Scouting is for those who want to be scouts. No losers, no cool kids, none of that applies to scouts, IMHO.
I do think that the long time in Cub Scouts is a dual edged sword. The first is that Cub Scouting is very different than Boy Scouting. I think some of the boys we recruit into Cubs thinking it was Boy Scouts quickly get turned off, and we lose them forever. Some would enjoy Boy Scouts, but don't like Cub Scouts. The second is that most boys who really like Cub Scouts are instant recruits for boy scouts. I think G2SS hurts us a lot, especially with Cub Scouts. I know there are reasons for those restrictions, but they are almost to the point of bubble wrapping.